My own solar system: Installing solar panels at my house


Uploaded by GoogleTechTalks on 08.10.2007

Transcript:
>> MURVEIT: Good morning and welcome. This is a presentation about solar energy basically
from the point of view of people who had it installed and then also from the point of
view of one of the people working in the industry. My name is Hy Murveit. I'm a research scientist
here at Google and I had the experience of basically paying somebody and having them
install solar panels in my house. But, then that's the typical story that most people
who have solar panels [INDISTINCT] would do. David Talkin is going to come on in about
25 minutes and he did it himself. And he put it in a house in the country without any access,
normal access to electricity and that's how he's providing electricity to his house. So
a totally different do it yourself experience David's going to talk to you about. And then
we're going to finish up with Kurt who is actually the guy I worked with to have solar
panels installed at my house and as he just said, in addition to working at Horizon, that
does the solar installations, he was a founding member of the Global Warming and Energy Committee
for the Loma Prieta Chapter of the Sierra Club and he's been working to fight global
warming for the last five years. He's really committed to this kind of technology. So,
with that introduction here we go. You know, you can take a look right here at the top
of my house. And the solar panels that I have that are working now and producing electricity.
So why would anybody here want to do solar electricity? You know, for obviously for the
good looks, right? You know, makes your house look terrific, makes a statement to the world
that you care. You can save money by producing your own electricity. And of course, you might
have to produce electricity somehow if you're like David and you don't have access to the
solar panels. Here's a picture of the front of my house. You know, it is a concern. I
mean, some people say what the heck is this? There's a recent new story about some guy
who is prevented by his homeowners' association to do solar panels. Here's the front of my
house. In my opinion, it looks terrific. But we actually we did have an issue where we--because
of the amount of shade I had around my house, we didn't have room to put all the solar panels
I would like and we actually had to put some panels in the rear and the rear is north facing.
Yeah, north facing so, you really couldn't put panels on. You know, in the northern hemisphere
you have to face south or things like that. And so there it's a little more obtrusive,
right? Because it had to be racked up to face the sun a little bit more. But anyway here
we can see an idea what these things look like. Before I get into the meat of the talk,
I wanted to talk just a little terminology. Many of you guys, maybe, most of you guys
understand this. But it's good to get it out of the way just in case. The difference between
power and energy and what you buy from PG&E or whoever your electric utility is. You know,
power is measured in wattage. You know, you can think of it as, as how hard something
is pushing. You're, you know, you're trying to lift a weight and what kind of force you
have to put on that weight. Energy is power times time. You know, you're pushing it for
an hour. That's the amount of energy you have to put out, that kind of thing. That's the
difference in power and energy. Power is measured in watts. Energy is measured in; you know,
like watt hours, so kilowatt-hours. And so you may buy from PG&E in the course of a month,
you know, 600, 700, 800 kWh of electricity a month and they'll charge you whatever, 10,
20, 30 cents per kilowatt-hour. And that's the deal basically you have with your--well,
have with your utility. And so, as I said that kilowatt-hours is the number I'll be
mentioning a lot during the talk. And this is how the PG&E charges you. Right now, not
everybody, not Google but most residential customers could get use this E-1 rate schedule
for electricity. And you can see, they'll charge you about 11 cents per kilowatt-hour,
add to your additional usage but then as you use more and more, your--the charge per kilowatt-hour
goes up. So the marginal charge could be quite high if you use a lot of electricity. Before
I started this project, my baseline usage was 380 kWh and I discovered I was using 1300
kWh a month. I wasn't paying a lot of attention to my electric bill and I have my electric
bills. And I was paying 36 cents a kilowatt-hour for each marginal, you know, if I turn something
new on, that's how much I pay. >> I have a question. Do you use E-1 or do
you have [INDISTINCT]. >> MURVEIT: I, right now, I don't use E-1
but-- because I'm solar. I'll get to that. So, just to show you guys, you know, and this
should be obvious but so here you are, here's a 650 kWh, I'm closer to this now but, user
and you know, with a $90 electric bill and but if you just double that to 1300 kWh per
month which is about where I was before I started this, I'll bill, yeah, triple the
electric bill, right? So that second 650 kWh cost you twice as much as your first 650,
so you can actually save money with solar energy if you intend to displace those expensive
kilowatt-hours. If you're trying to displace those cheap kilowatt-hours that's actually
harder to make this money saving deal. But before you get into--I mean, basically what
happened with me is I decided to do this solar panel thing, solar was hot, I said let's get
into it. I call up Kurt and I say you know teach me about this, I want to buy this from
you guys. And he comes over with a whole bunch of light bulbs and things like that. And says,
you know, "Well, before you were played, you know, you displace the energy, let's talk
about saving energy. You know, do you really need to use all you need to do? And that's
really the right idea. So, I get a sort of, you know, bass-ackward, as they say. I would
recommend that, you know, even before you start this project go figure out how much
electricity used and see if you can save some. And I'm going to through what I--what I went
through. So, first thing you got to know is how much you're using and then where you're
using it. And there's a number of ways of figuring that out. Obviously you can look
at your utility bill and see, you know, how much they're charging you. It'll tell you
right there how many kilowatt-hours you're using a month. You can use a device like this
called the "kill-a-watt" if you're curious about any individual device and just plug
this into the wall. If it has this kind of plug you plug into that and it just displays
you know 70 watts, 300 watts, whatever, whatever it is you're using. You can use your electric
meter to see how much energy your house or how many power your house is using right now
but obviously you can look on the web and see what a typical refrigerator or whatever
uses and they're usually pretty close. There's many things that you can't really measure.
You know, what's the power consumption of my, you know, pool or something like that.
Pool filters, something like that, where it doesn't plug-in, it's been wired into the
house, how do you--how do you deal with stuff like that? And the way I wound up dealing
with stuff like that is looking at my meter. And this is the old-fashioned meter that many
of you would have in your houses. And you've probably seen it, you know, this thing spins
around and every time it spins around it shows you a certain amount of energy used. This
is the dial that tell you how much you've used. You know, at the end of the month PG&E
comes out, they read it, they read--you know, they have written down the previous months,
they subtract send you a bill. The interesting thing about this is there's a little mark
on this dial, it spins around and you could, you know, there's just one mark on it so every
time it comes around, you know, you could measure how much time one revolution took.
And you can see right here on the thing a little number, 3.6. Well, it turns out that
tells you how many watts each--watt hours each revolution is. And so by using this little
formula you could--you could realize that, oh, if it took 10 seconds to go around that
was about 1300 watts that you're using currently right now. And, you know, let's say you turn
on a 1000 watt appliance, that should go up to 2300 or, you know--you know, the 10 seconds
of that and 3 seconds is that. And so, I would do stuff like that. You know I would turn
on my pool pump or my outdoor lighting and just notice the change. Of course you have
to be careful that the heater just didn't kick on, or the fridge didn't just kick on
and stuff like that so we have to do multiple measurements. But that's the idea of how you
can do a little audit of your house. Well, I started doing my audit, the first thing
I noticed was my pool and there is my pool pump and it was using a whopping 400 kWh per
month because the pool guy had said it to basically filter and sweep and--and use motors,
we're effectively on 11 hours everyday. This is in December. I mean, we don't use the pool
on December here in California, at least in Northern California. And we're using a lot
of unnecessary electricity and I won't go into the details but the bottom line is, you
know, in the wintertime I save almost 300 kWh a month just turning that down. And then
in the summertime a significant amount and on average, I mean, throughout the year, you
know, remember I started with a 1300 bill and I--per month on average across the year
probably got rid about 240 kWh. And I'm telling you that I was spending over a $100 a month
just on electricity to filter a pool. Halogen lamps, a lot of people buy these, they're
like really cheap, they're like $10, $20, $30 at Costco or somewhere like that. This
300 watt halogen lamps, amazing users of electricity, in fact you'll figure out, I think a typical
user will spent a $100 a year in electricity for your $20, $30 lamp. And it's sort of a
falsely kind of--anyway, I had a couple of those in high use areas that I replaced and
I think I saved about 40 or so kilowatt-hours a month. If I did this little half to mine
or I replaced, I switched it to a non-halogen version and I, you know, put in a couple of
compact fluorescents in mine. And now, I actually I found that you can buy fluorescent versions
of these things and that's probably the way to go. They're a little more expensive, they
may be like $70 instead of the $20, $30. But, actually over a year they're a lot cheaper.
We have a lot of lighting, you know, the obvious thing people tell you is, you know, replace
all your lights with compact fluorescents, I did that. I also found though that I had
a lot of these fixtures in the ceilings, these are 150 watt halogens in high used areas.
And I actually went and replaced the fixtures themselves. That's a $100 investment for a
fixture but it probably saved me in the long run, especially if I wasn't going to solar,
it would have saved me quite in the long run, it's not a good thing to do anyway. In the
end I replaced around 2000 watts of lighting in my house with about 450. But quite honestly
there's a lot of lighting left that's sort of harder to replace. Computers are another
story. We have, you know, for the four people in our house; five computers are probably
not the only one with that kind of ratio in this room. And, you know, as a few of them
were left on 24/7. The 24/7 and I'm not even talking about monitors, just computers, 24/7
computer probably cost, you know, well almost 40 kWh, and just for that one computer and
then, you know, it doesn't need to be on at night. But you can save a lot. So anyway,
bottom line of my energy conservation project, you could see that the top was my original
usage, my new usage after doing these, basically these four kinds things was there, you could
see I saved myself about 400 kWh a month. The funny part about this story is we started
this project with Kurt before I did this, so I had this system designed where, you know,
it was going to actually pay me back in I don't know, 10, 12 years. But, because of
the fact that I saved all these energy and I didn't change the size of the system to
pay back, you know, it's probably marginal at best. That's not a bad thing in my opinion,
you know. But, you know, if your goal was to just make it pay back, you know, at that
point I could use the more smaller solar system or I could buy myself a cool electric car,
right? And use more electricity that way. So that's the end of the conservation part.
Then let me talk a little bit, you know, about--well, let's--what is the solar panel system? At
least from my point of view, the layman's, if you will, point of view. What do I know
about that? Well, you know, this is the sort of your basic block diagram. You have your
solar panels on your roof. They generate DC electricity, not AC, not the kind that you
can plug your TV into, right? So you got to convert that to AC and you do that by these
big devices or, you know, these electrical devices called inverters. You know, I had
a pair of 3.3 kilowatt inverters. At Google we have 150 kilowatt inverters, this mean
have a lot more solar panels. But, you got the idea, you can convert that to sort of
basic house electricity, gets mixed into your electric panel where all your electricity
goes. And keep going to your house and it can go out to PG&E, if you're producing more
electricity than you're using, you sell it to PG&E. If you're producing less or none,
you can buy it from PG&E. And that's the basic way that the system works. David is going
to talk pretty soon about what happens if you don't have a PG&E to sell you electricity,
well you can have basically the same set-up except the panels go to some batteries that
store it. In my case, PG&E are my batteries effectively. So here's a picture of my panels.
You've probably seen some solar panels since there's 9000 of them scattered all around
Google. And they're--I'm not using the exact same kind but they're very similar. And they
are about 13 square feet. About five feet by two and a half feet each panel. As you
can see they're installed in these grids, so you pack them pretty close together. They're
very sensitive to sun, to shade and clouds. You know, direct sun hitting them is terrific,
cloud flies over; you can see that production shoot down. They're somewhat sensitive, not
nearly as sensitive, but somewhat sensitive to sun angle, you know, if the sun's hitting
them square on, that's a lot better than an oblique angle. And they're sensitive to temperature.
Sadly, when it gets warmer and the sun is better, the efficiency of the panels actually
goes down somewhat, 10% or whatever. They're spec'd, if you really—-you get the spec
sheet of my panels; they're spec'd to 215 watts per panel. Practically speaking, mine
don't go over a 155, 160 watts. So that spec is under ideal conditions and those ideal
conditions just augment. So don't go, like I did, naively when I started this project
and multiply 215 times the number of panels and expect that that's what you're going to
get because you won't. The sun, this is how much power the sun puts out, about a thousand
watts per square meter. You can see these panels per meter generating 155 per, you know,
1.2 square meters. So it's getting what, 10%, 20% of the--of the energy the sun is putting
now. >> This performance persists with age or do
they degrade a little bit? >> MURVEIT: I think they degrade at like a
percent a year, something like that, Kurt, Kurt can mention that.
>> NEWICK: A quarter. >> MURVEIT: A quarter percent, sorry. These
are the inverters. Like I said each of these can put out about 3.3 kilowatts. I have two
because I have a six kilowatt installation that actually on a typical sunny day puts
out about 5 kilowatts, you know, in the middle of the day. And if you look at them you could
see that they'll tell you, you know, how much, this contains how much power right now 2600
watts and that day so far I had put out 27 kilowatts. And so, that's the panels and then
the inverter and then they're connected out to the mix, to the--your electric box over
here. You notice it says, this electric box is serviced by PV, by PV system and so, you
know, somebody, you know, shuts off the utility power and goes to work on the electricity
in your house and that's an electric you can sell with the solar panels, right. They got
to know that because, you know, a typical house doesn't have multiple sources of powers;
you've got to inform PG&E and stuff like that. That you have you switch meters when you install
a PV system as well and you get this new digital meter, and the reason you get this digital
meter is because you're going to switch over from that electric plan, the E-1 plan that
we were just talking about to a time-of-use plan that where you rate actually varies by
the time of day. That's the kind of how Google is billed and that's how you want to be billed
if you have a PV system. What happens in this kind of time-of-use is that, you know, peak
hours where there's more demand on electricity, you're charged a lot more than non-peak, as
you could see. But the good news is in peak hours, that's when the sun sell, that's when
you're selling to PG&E. So you get to sell to PG&E at $29 and then you buy back in the
evening at a dime, so you want that. You can also--say, by the way in the winter, it's
different than in the summer. And again, there's just more demand on, you know, the utility
than in the winter. So we move on to where to place the solar panels. If you have a lot
of sun and you don't have the restraining issues, it's really not a big issue. You know,
you get some nice southern exposure roof and put your panels there, figure out how many
panels in one, Kurt will talk to you about that, and off you go. But, as you could see
from my house it wasn't quite that easy. The fact that you look to the south, there's these--what
kind of trees are those? >> Monterey Pine.
>> MURVEIT: Monterey Pines, right? >> They're our neighbor's.
>> MURVEIT: Our neighbor's Monterey Pines. Our favorite trees in the world. And they're
right to our house which isn't a problem in the summer, but wait until the fall and the
sun angle gets lower in the sky and those things are going to shading my panels and
my production will go way down in the--in the fall. To the west, there's these trees,
so in the evening or the late afternoon I'm going to lose a lot of energy by that. To
the east, so in the morning I lose some, but, I do have some sun in the middle of the day,
that's enough to make this project worthwhile. So how do you figure out where to put the
panels? There's a picture of Kurt, he's going to be talking to us, on my roof, surveying
the roof, trying to figure out where the heck to put the panels. How does he do that? You
see this device called the solar pathfinder, we have one here you could look at. More or
less, you put it down and level it and you can see well, here on the slide there, you
could see, what the sun, you know, what part of the sky--will the sun be hitting this part
of your roof at what time of day, what time--what month in the year. So for instance, over here
you could see that at one o'clock in September it's sunny but, you know, right there at 9
AM in September it would be behind that tree and more or less you can survey your roof
and decide where. And you can see that those trees that I had on the--whatever part of
the sky that was, in the southern sky, I guess, oh no the western sky are causing a lot of
shade during that part of the year. And then you could see right there, I'm losing electricity
and I believe in the end my entire solar system is only about 60% as efficient as it could
be, because of all these trees. So and Kurt did an analysis of this thing and he came
up with the prediction of the performance of my system and there it is. The lighter
part is the prediction and the darker part is the actual performance for the four months
I've had the system so far. And you can see it's pretty much right on. And there are actually
some panels that I--I mean, an inferno that went down that month so that's actually was
pretty close to the prediction that proved correct for that. Installation is--was a snap.
I mean more or less I paid the money; it was installed in a few days, with no issues. It
was great. I talked about the rear panels having to be installed on these racks. I'm
going to show you the effects of shade. The--you could see at 10:15 and at about 3:45 this
time of year, I'm out of the--the sun starts shading a panel. By the way, once one or two
panels are shaded, panels that are wired in like strings of eight or nine, at Google there
are 14 I think. They could be as low as 6, but anyway, you have these strings that are--that
are in series and then connected in parallel. If one or two panels is in a little bit of
shade, that string is more or less gone. That's just the way they work. And I'm not sure of
the reason. But, anyway, so, anyway, you can see as we're coming out of the sun, at 10:15
we start to go up to full power, you know, for that there's much power it's going to
get for that time of day, that's pretty well, till the sun hits those other trees that I've
shown you and we get shaded there again. So, shade has a significant effect. Clouds, you
know different kind of shade, instead of a tree, you're shaded from a cloud, big deal.
Here's a clear day, here's a cloudy day, can you see the difference? Obviously, there's
a lot of cloud that part of the day. An interesting factor though is you'll see it actually peaked
higher over here, than it did, well, that's the wrong slide, sorry. Well, whatever, you
saw it peaked higher over there. It doesn't seem to want to go back. And so, I think that's
because of the temperature, I thinks it's actually cooler on the cloudy days. So, when
it wasn't the sun, it was--it was moving. Ah, we're back. Okay. Let me talk about--oh
yes. I wanted to talk about temperature. Again, another example of temperature; one day, I
went on my roof and I cleaned up my panels because you get these new set of solar panels,
they're so cool, I'm keeping them clean, you know, it's the pollen messing me up. The answer's
no, the pollen's not messing you up, but when you up on the roof and you hose down your
solar panels, what happens is you cool them off. And you can see there, by cooling them
off, I actually have this big spike in performance. This just shows you how temperature affects
things. I built this monitor for, you know, instead of going on my local website where
you can see the performance of my system. I wanted to give you an idea of what my system
performs like for the course of a couple of months, so take a look at this. Here we are
at the start, this is the end of May, start at June, and you can see we have some clouds
and what not. Those things are little glitches in the inverters, by the way, that SunPower
is going to come and fix for me. It's only costing me about half a percent overall performance,
but you can see that in there. After a while, starting about here, we're in now mid-June,
things get pretty sunny. And then they stay sunny pretty much for the rest of June and
July. There was another cloudy day but you get the idea. Performance for me stays pretty
close to 30 kWh a day. There you go. This is the performance overall, over the year.
We had a cloudy April. That's when my--one of my inverters went down, I went to half
power. And then, more or less, since then, until yesterday, things were pretty--were
pretty good. The last slide just shows you--when I announced this presentation, I got several
emails from people showing that they too had installed solar system and a few them have
put up solar websites. And so, these are sites, the top three; mine, Dan Halem's and Steve
Lacy's, who may or may not be in this room, I don't know what they look like. Their websites
or how their solar system been doing, I'll leave this up for a minute. David get ready,
I'm ready to switch over to you. And then this is of course our Google system, right,
that shows our--you know, I have 32 solar panels; I didn't mention that on my roof.
Google, you know, has 9000. So, you know, about a factor of 300 more. So we--of course,
you probably heard, have a webpage that shows the performance of that system. So, with that,
David are you ready to take it away? >> TALKIN: Yes, indeed.
>> MURVEIT: Okay, go for it. >> TALKIN: So, brief, I'm going to talk about
a system that we have installed in Southeastern United States, in Virginia, at my country
place. We actually have a bit of history of it. We've been tinkering with solar since
the '80s. We've only recently gotten serious about it. About three years ago, we built
an octagonal cabin and we put in a proper well and put in a 240 watt direct solar pumped
well. So it's a deep well pump that does not involve leverage or anything, it just pumps
directly into a tank. It's stored and then the gravity will seep the tank to the house.
We have a 480 watt battery converter setup for that little cabin and it gives us enough
electricity for our refrigerator, computer, lights and so forth. I have a satellite Internet
link so, I can actually work from down there. And not only will [INDISTINCT] there's this
so called modified sine-wave and I'll talk about all that later. But, in general, that's
[INDISTINCT] get a three-sided converter. And we're now in the process of building a
full-sized house and that's really where this particular story begins. So there's the old
cabin that we built in 2003. And it's just a one room meeting and kitchen basically where
we have parties and hang out when we're camping. And there's the 480 watt array with these
little set of batteries and inverter on the pole there. It's a primitive charged controller
that keeps those working batteries charged. By average this 12 volt system converts from
the 12 volts [INDISTINCT] AC through that modified sine-wave converter. Now, our new
PV system was--the motivation behind it was--contrary when the powerful power tools and we actually
did put it down there. And nobody wanted one of those new generator drawn throughout the
construction. And I thought it'd be kind of cool to show the construction workers and
others in the area, the locals, what could be done with solar so, we decided, we ordered
the equipment. Beforehand, we went down there and quickly installed a temporary system so
they're contrary to [INDISTINCT]. So, I found a really good deal on 180 watt modules, I
bought 30 of them. They're 24 volt modules and we're going to run them at 72 volts AC
of the input battery charger. That's three of the panels in parallel and put ten--three
of them in series and ten of them in parallel. So it gives 72 volt input to our battery charger.
The batteries themselves will be of 10 setup to be of 40 equal battery line. We got an
excellent power point tracker, Hy didn't touch on what that is, it's a very important thing.
Solar panels are basically a constant current device. All these perfect constant current
devices so, the amount of power you get is dependent on what voltage you're pulling it
out of. So you want to pull as close as you can really to their--to a high voltage or
something close to their maximum voltage, really about something about 75% or 80% of
their maximum voltage. So, their maximum power contrived basically impedes expansion device
between the panels can output what the batteries and other things can stock up. I'm going to
use on the house, a 24 kWh of storage. That will be 12 of these green batteries, a 115
ml batteries. And relatively cheap, I get them at Costco for about 60 bucks a pop. On
the--for the temporary setup of the contract, we're going to install 10 of these panels
that will 21 60 watts and I'm going to have 8 kWh of storage. And that will be plenty
since they usually use it in short bursts. And I got a couple of really nice heavy duty
pure sine-wave from [INDISTINCT]. They're not really pure sine wave, they got about
5% of distortion but they're really amazing in [INDISTINCT]. They're 3600 watts each.
I got two of them being hooked up, out facing a 240 or 110, I don't know, 240 or 120 volts
ACL. So, here's a sort of block diagram for those of you who have [INDISTINCT] sources.
We've got the photovoltaic array, which is this sort of a constant current source which
slides current for a voltage center, puts out power of around 72 volts. You can short
it down to zero volts, concealing and sledding with current. So, you want to keep it up close
to that 72 volts. That's what the maximum power point charge of that is. It impedes
much of it down to the 48 volts of batteries it's going to use. And also a very--has a
very fancy control logic that keeps the batteries happy. [INDISTINCT] batteries are very finicky,
it usually downs when--if you don't charge them properly and quickly and promptly. Just
leaving your batteries set flat, that is enough to take years off its life. So, the batteries
themselves in the alternate system will be 24 of these 115 Ampere-hour, 12 volt marine
lead-acid batteries, hooked as 4 in a series, 6 parallel to give you 48 volts of storage.
The batteries down, again their voltage is 48 volts and that's the input DC to the inverter.
And the inverter's setup with an autotransformer so, I can only have one inverter from that
point and will still get 240 volts or if the load demands it. The load inverters will come
on, it's flat up to the 7200 watts. Of course, until the batteries go flat. And the rest
of these--most of the rest of the slides, I'm just going to show you the legacy of putting
this little cam array setup for the contract if we dug 10 poles of these feeder posts and
used internal chord conduit for the rails and a little--I should put panels on, this
is all the stuff you get can get in Home Depot or Costco or where you ever, loads whatever.
And there we have a little bit of a caveat because an 18-wheeler pulled up at the end
of the country road and wanted to unload the panels and of course we're about four miles
from there, and so we had to slide the 1300 pound pallet off of the lift gate of that
18-wheeler onto my friend Nick's truck there. And my heart is in my mouth most of the time.
So that's 30 of the panels at around 1300 watts--1300 pounds, including the weight of
the pallets are worth. So these are the 12 that we pulled off of the stack that we used
for the temporary setup. And that's what it looks like when they're lashed to those rails.
And we've only a trash can cover for our electronic gear and off to the side there you see a typical
[INDISTINCT] contract that we used and in fact we tried our best to short out the inverters
to see if it was going to be any trouble so I cut that Boss stitch two and a half horsepower
compressor and basically I almost pumped up to this working pressure of 120 pounds and
then plugged it. I plugged it back in again, when you do that that basically puts the maximum
pump loads as you can possibly ever have. So I did that while I was reaping with the
seven and a quarter inch [INDISTINCT] steel saw which also draws that thirteen inch when
you kick it off and the inverters didn't even run it. They just--they just performed beautifully.
So here's this larger scale picture, you could see inside of the trash can cover the two
OutBack inverters and the big box on the left is the AC output and the box on the right
is the AC input switching in shunt--AC shunts and other things. At the top of the ceiling
outside may be the OutBack Charge Controller. And that's the [INDISTINCT] between them.
Panels and the batteries and also keeps the batteries happy. And here's a closer up picture
of the same thing. And I can't really recommend this OutBack set of two arrays, it's just
adjoined use, a very robust--at one part I have the inverters wired up so they were in
facing instead of out facing. Of course that probably means--which means that they were
dead short. Driving in one night and I switched the thing on with the--with the air compressor
on it and it groaned a little bit and then I decided it was--it was going to pack it
in, it turned itself off and then, you know, when we started up the compressor it's just
fine. I did it about five or six times until I figured out what was wrong and then the
more I tried it, the more it wanted to... So here's the finish setup there. And that's
what those contractors are plugging into; they've been using it now for about a month
and a half. The system's fine, they brought--they keep bringing these things over to plug in
to see if they can break it. And there's my house under construction. It's actually never
well done. So what did we learn? Well, I thought about bringing up this temporary setup for
the contractor, I thought it'd be a piece of cake and I'd have it all done in a couple
of days. We spent--me and my friends spent four hard days together and then I spent another
three days by myself tidying it up. It was a lot of work. Something bad or in our case
the worst thing was--because you're having this stuff delivered four miles away and dumping
it off the back on 18-wheeler instead of having it delivered to the site. And a few other
minor things but don't go into something like this thinking everything's going to be smooth.
Always estimate longer than you think it could possibly take. And pay for good components.
I've been through a number of cheap inverters and charge controllers and having work that
OutBack setup [INDISTINCT]. And by all means use pure sine-wave inverters because the sort
of modified sine-wave they put up certainly on wattage for sure. And if you're heating,
order with [INDISTINCT] resistance of something sure you get that much wattage but you're
drawing and deducting loads from your refrigerator or something like that. Power pack is terrible
and it makes the motor run hotter and you don't get anything lifetime or actual power
you'd like to have. Shop for half the prices, I ended up buying my panels for about half
the going rate and very fine panels. Worry about battery care and feeding. There's sort
of a common lore and often resistances, the first time you get your battery pack, you're
going to install the thing and run your batteries and then you get up some battery. Start up
by learning how to take care of batteries because they're very--they'll last a relatively
long time if you take care of them. You can ruin them overnight literally if you don't.
But in certainly off the grid, it really, really works and as Hy pointed out, when he
was starting to setup his system. Having this solar power available on site really makes
you think about where the energy comes from and where it's going. So that's what I want
you to have. >> NEWICK: Can you hear me okay? Okay. Here
we are. Start my presentation there. Okay. It'll come back up in a minute. I'm just looking
at blue screen anyway. See, do you press the arrow key to see this one here... [INDISTINCT].
There we go, okay. I'm Kurt Newick, founder of Global Warming
Committee with the Sierra Club and blah, blah. This is what shading does. I'm going to go
back here, hopefully it'll go back. Does "P" go back? This is shading on a cloudy day.
Shading is very important and very sensitive, on a cloudy day, it doesn't matter that much.
I'm going to go back. "P" should go back. It doesn't want to go back. The arrows go
back. Okay. There's shading on a cool day, okay. Just go back one, all right. This is
just a little pine tree that shades your array and there's your two converters. It's normally
a bell-shaped curve. This is time on the X-axis and power on the Y-axis. Just a little bit
of shade that strikes your array, knocks out the production 40%, peak production. So I
wanted to draw that into your head to get a good shade in analysis. Very important if
you learn nothing else. This is the same array on a cloudy day. In a cloudy day, there is
technically no shade because the sun scatters in the clouds that comes down evenly. So on
the same array; it only gives us 14% of its energy, on a cloudy day. So, if you have some
shade in the winters, it's not as big of a deal because it tends to be rainy and cloudy.
I'm just going to breeze through some pictures. There's triangular modules put on [INDISTINCT].
They're on there with the Boss. That's what they look like in installations. This is a
wood shade [INDISTINCT] taken in Paradise. It looked nice when they're in even rows.
And compare that with that. So, this is a strip mining coal operation, that's a valid
comparison in aesthetics. I love that picture; I had to throw it in.
>> [INDISTINCT]. >> NEWICK: I pressed the arrow key twice so
it's going to [INDISTINCT] twice. I'm going to try to get off the system. [INDISTINCT]
to stay here. But anyway the next picture--I guess this takes a minute here. Now I'll be
four slides ahead, so I guess we have to speed up [INDISTINCT] when Peter catches up to us.
That is going to be a SunPower installation. There's--I'm going to go through it at the
end, I have a fact sheet over here, anyone wants to size in, these are technical formulas
I created myself. Okay. Here's the solar arbor. Okay. That's our best looking system compared
to the previous slide. We built arbors too. Okay. Just kind of have to wait for the computer
here, that's the story of our life, wait for the computer, right? These are the important
benefits of solar: rising electric costs are avoided, solar costs less upfront, when you
finance it, anyone over a $100 a month on your electric bill, it's going to cost you
less money to take a loan and pay that and you own the systems, like all in a house.
Investment is recouped upon resell. So your principal's protected because when you sell
your house, it will be worth more than what you paid for the system. And the really kicker
is these appreciate over time, so your savings increase over time, as cost of electricity
goes up, and I have a graph to show you that. But most important thing of all is not money
in my book; it's the success of the human species. If we fail to put in solar, we may
fail as a species. That trumps everything in my book. PG&E solar payback rates, in graphic
form probably had a great thing in the summer. You can see it's twenty nine cents a kilowatt-hour,
noon to six. Three and a half times the rate as when you use it of nine cents in the summer.
So you can just size a system 38% smaller and the self facing sunny array, 38% less
cost and still zero out your bill using the time you use rate schedule, it's huge. That's
why so many people put in solar in California. Net metering is just when you get retail credits,
when your meter goes backwards you get credit at the retail rate, whatever that is. And
the summer excess can be applied to the winter; it's on the tool up in the billing cycle.
And you get a three to one ratio during the summer. When the meter goes backwards, it's
three times as fast as when you push forward because your credits are worth more. And you
get full retail credits. This is how much solar costs. This is what the great way to
look at it, I love this slide. There's three different users, one is 600 kWh a month, which
is about normal. One is high--medium high and on is very high, 1350. So you see the
highest user is paying $326 for the electricity every month. And this is going to cost after
rebate, so they'll probably be billed less than that with the SunPower there, conservatively
47K. Over the course of 25 years you spend 47K upfront, after 25 years at 5% of electric
price inflation you will have saved $158,000 for the base system. And that's a 335% of
what the system cost. Most people are closer to one of these two, the medium or small and
I just wanted that spike. Let me go to the next one. This is why I put in solar, I also
love this one, what could electricity cost in 1970, that's 2 cents a kilowatt-hour. What
could it cost now, well it depends on what you are paying, that on average, is about
14 or 15 cents a kilowatt-hour. So, and that's going to continue that long term trend as
fossil fuels run out. So, you're really protected from this kind of thing, the solar, because
it's free to operate once you pay for it. I'm going to wait for the computer now. I
guess I used arrow keys. So, I just want to make it clear for my class I guess, on August
25th, here we go. This is how the size system--pick up the fact sheet on the back, basically take
your annual electric usage and here's the formula, an AC watts of the system size you
divide it by 4.4. So your average daily electric loads--excuse me, divided it by 4.4, just
go through the formula. 20 kWh a day is normal, divide that by 4.4, so to generate as much
power as the average retail electric user needs, you need a 4.5 kilowatt AC system size
or that's without a time-use-meter. To zero out your bill with an E-7 PG&E time-use-meter,
you divide your average electric load by 7 and you can actually put in like a 2.9 kilowatt
AC system size and you have a zero bill, a substantial savings over 4.5. So there's kind
of two ways to look at, those are the formulas, many people have their own. This is assuming
San Jose, California which gives the equivalent of 5.4 peak sun hours in the south facing
sunny ray. If you're facing a different direction and a different location it maybe different.
This is my class, August 25th, I go through tons of details, it's a great class, you're
welcome to come to that. And that's what I have. So, we've got questions now I think.
So who's first, yes? >> So, if you have...
>> NEWICK: Oh one second, oh okay. Do we have a microphone to pass around or...?
>> [INDISTINCT] you don't have one... >> That's all right.
>> NEWICK: Well, you can use mine, I guess. >> If you have to $2000 to spend and you want
to save the world from global warming, how effective do you think getting solar panels
on your house is compared to other things you can invest the money in?
>> NEWICK: Great question. Let's say it is all individual, depends on the person. Solar
power is renewable energy and this wish to global warming is a way to create power responsibly.
If you can do things to save energy, it might be cheaper to conserve but eventually you're
going to have to get your power from somewhere and I say wind power, solar, any renewable
energy is the source that you want. >> MURVEIT: Okay David just--is David's microphone
on? Feel free to pipe up if you do want to answer these questions.
>> TALKIN: Ok, will do. >> NEWICK: Who's next? Okay.
>> Can we pass the mic? >> NEWICK: Pass the mic over here.
>> I wanted to ask, I guess David and Kurt about the LED batteries and their lifetime
and if there are other better solutions, or. >> NEWICK: Well, really the only way, to...
I guess this is on... Batteries are great if you're off grid, if you're on grid, I'm
really against them, I'm not a fan because they are expensive, they are inefficient,
they wear off and are toxic, that's why. But, if you're off grid they're great, they're--you
can just care for your batteries and do you want to talk about this on the other side
there in New York? >> TALKIN: Sure.
>> NEWICK: Yes. >> TALKIN: Sure. Carefully taken--batteries
carefully taken care of can last about five years. And they're actually amazingly recyclable,
when you return the battery as a core and get your new battery. There's no additional
pollution, just taking it all and turning it back into another battery. So, they're
pretty ugly things and I tried--I resisted for years of getting involved with batteries,
that's why my original [INDISTINCT] setup was a direct solar. And I spent a lot of time
planning and scheming how I could build refrigerators that would be direct solar and everything
else. But I agree as to batteries because, otherwise you're talking about buying a lot
of specialized or inventing your own specialized equipment that cost much, much more than these
standard equipment. And it doesn't really have the payback, for instance, you can get
a refrigerator that's designed to be direct solar. But, the refrigerator alone, for a
very small capacity refrigerator, sometimes 5 and a half cubic feet cost around $1600.
And it requires DC going up right to the house. So, now you're talking about the big fat copper
wires to bring in DC to the house versus having batteries. Well, copper's a--copper mining
is a problem as well. So, I hate batteries but, I just don't know what else to do. And
keep in mind that there are new battery technologies coming online, that are more efficient than
as the Lithium Ion and the Nickel-Metal Hydride batteries that are showing a lot of promise.
So, yes, I agree, batteries are a [INDISTINCT]... But, off the grid that's what you got.
>> NEWICK: Yes. They're working good and they're perfected. The lead acid ones are great long
life, will go 10, 15 years. Another question? Pass the mic over there, go ahead.
>> So, I have a solar system and actually it's my second system, second house. And I
had E-7 for a while, and I thought that didn't really work for me because I was consuming
more than I was producing. So I never had the pumping at three times, or whatever. You
know, we're common of that--so, what I have now is I have a solar system but I'm using
the E-1.
>> NEWICK: Depends on the size of your system when you use energy. If you're welding in
the afternoon, you don't want E-7. It all depends, everyone uses energy different times.
I reprogram this pool a lot of different times, so, it--you try to conserve noon to six. 95%
of the people, we do like the E-7 rate schedule, some people may not care about bills, or put
in a bigger system, 30% bigger you don't need E-7, you can generate much power, so why don't
you put in a bigger system. But, almost everyone puts in E-7 for their benefit, unless you're
welding in the afternoon, or you may have too small of a system or something, I'm not
sure. We can go over that offline, if you want. Another question.
>> MURVEIT: One second, I just wanted to mention. So in our system, but you know, they're sized
a little bigger, we're significant producers in the afternoon, you know, from noon to six.
And right now, on the summertime, when I turned on my pool pump, without the pool pump we're
actually slight consumers of electricity overall. But, you know, it's strongly producing and
so for us, it works out. I'm a little worried actually in the winter. See how that goes.
>> NEWICK: Yes? >> So you mentioned the importance of the
angle of solar panels. So, if I have a house where the roof is pitched, you know, let's
say, this is south, is there basically no hope for me?
>> NEWICK: No, west works great too. The appliances facing west, west or south are equally good
financially, south will out produce over the course of the year, as long as it's not too
steep on the west, a 4 and 12 left pitch is really very, very good. But east, you want
avoid, because the time used rate, you want it to face the afternoon sun, west is fine.
>> TALKIN: I just wish to that... Can I add to that?
>> NEWICK: Yes. Go ahead. >> TALKIN: You don't have to be too worried
about whether you're 5 degrees off, one way or the other. The computation less the price
paid for--it's the cosine of the error angle, as the error for the normal. Is really all
you have to worry about from all the angles. Anything, I'd have to say, 15, 20 degrees
off, the loss you're going to see is equivalent to the sun projection on to that panel.
>> MURVEIT: Yes. And to add my two arrays are sloped significantly, differently, right.
So, the one that goes on the back is what, something like a 5% slope and the one, you
know, facing the west is more like a 20% slope. So, you know, you can see that, you know,
so the back array is better in the mornings, which is optimal for--from a PG&E point of
view. Maybe from a global warming point of view it's irrelevant. But from a PG&E point
of view, it's a little different. But, you know, it's ok, I think that's a minor effect
as long as, you know, you're in general facing the right direction is the major affect to
clouding effects. >> I'm interested in the solar cell industry
itself and how the $9, $10 might change over the next 5 years. You know, if you're thinking
to buy. >> NEWICK: Yes. The rate is constantly recovering.
It's gradually going down; the rebates are going down two to three times faster. So,
if anyone is considering solar, get your [INDISTINCT] right away. And that's been true--you know,
the best time to buy solar was three years ago. The rates were 450 on rebate and the
equipment cost has actually gone up a little bit because demand is so high. But I think
it's kind of peaking now, there's been a huge long downward trend of panel prices over the
last 20 to 30 years, now they're kind of leveling off, and they're gradually going down. And
they will continue that depending on supply and demand but, the rebates in California
go down two to three times faster than the cost of the gradual decline.
>> How much--I understand is the equipment cost versus labor?
>> NEWICK: Oh yes, the equipment, the solar panels about 60% of the cost, inverters about
10%, and everything else is about 30%. The rails, the electrical installation, the permitting,
the inspection, the--all the other whatnots is 30%.
>> TALKIN: Can I just add that my off the grid system has ended up costing me around
$4.50, and it's called what? Plus a lot of burnt shins and bruise knuckles and...
>> NEWICK: Another question over here. Go ahead.
>> So, I have received a few bids and two of the bids are almost exactly the same. The
only difference was that one company's using BP panels and the other is using Sharp panels.
Are there any difference? >> NEWICK: Those are both great panels. It
doesn't really matter as long as they're costling technology. Any of the major manufactures
have fantastic products out there. Those are all reputable manufacturer, Sharp, I personally
that's my favorite between those two. But I don't want to say bad things about the other
company. But Sharps are very, very high quality in my opinion.
>> MURVEIT: And I mentioned, you know, at Google here we have the Sharps on the roof.
My house has the SunPower ones. They seem to work fine. My issues have never been in
sun, you know, arrays. I don't know if anybody here is in the solar project but I forget.
They, you know, they installed 9,000 panels. They were a pretty good idea of how many of
them malfunctioned. I seemed to remember hearing like one and two, you know. So, the product
seemed pretty good. I'll say this about that though, about, you know, picking contractors,
we got two bids. I got one from SunPower; I got one from Solar City. And you know, I'm
sure they're going to--they would've been fine either way, quite honestly. I wound up
picking, you know, who my gut told me would have been easier to deal with. And maybe Solar
City would've been fine too. But, you know, I just got more warm fuzzes. And you know,
the truth is, you know, things do happen in a--in a project, or we, you know, I--Kurt
and I get--we're on the roof for three hours one day changing our design. You know, I think
in the end if you see small differences in prices, you know, you pick who you think,
you know, for you is going to be easy to work with and then work them. But, I think the
good news is that probably most of the contractors around here are quite good. I know lot of
people for instance who got Solar City jobs done and they were very good. So, I could
go either way. >> Thank you.
>> So, I'm just come out there, I have my panels coming in through Solar City. And we've
been--I'm sorry. I'm getting my solar panels in through Solar City and they seem pretty
good. I'm sure definitely shopped around but my focus [INDISTINCT]. I forget, sorry.
>> [INDISTINCT] don't you think? >> NEWICK: Yeah, the solar contractors are
a very responsible bunch of people. People go in the business because it's the right
thing to do, not to make a lot of money. So their hearts are in the right place. When
you're choosing the contractor would depend on experience, trust your gut, interview your
contractor, find out their credentials, what their experience is and then trust yourself
and go for it. Because I don't think I rarely heard of [INDISTINCT] it's something I've
never had. People have difficult and satisfactions with different solar contractors but, we [INDISTINCT]...
>> My point is that the panelists themselves, they generally have manufacturer warrantees
of, what's it like, 20 years? And the expected lifetime with the panel is more like four
years? So, and also--I don't--I don't know how many companies do this but, probably a
fair number also have the installation guarantee is for a certain period as well.
>> NEWICK: Yes, it's required. And your installation guarantee with California Solar Initiative
and the panels have 20 to 25 year warrantees and they'll go 40 plus years.
>> MURVEIT: I want to just put up a quick slide about the question on solar angles.
I mean, let's--you know, the angles for the sun for a second. You can see here, you could
see my two arrays. The green line and the--and the blue line on the bottom, right. So the
green line is the front array that's tilted 22% toward the west, I guess. And the blue
line is like, whatever, 8% toward the west. And I actually have 18 panels in green and
14 panels says blue. And so you could see, no, it should be, you know, there should be
a big difference in the production rate of more panels. So you could see as, you know,
in the earlier part of the day where the sun angle is favoring the blue panels you see
they're about equal. And then you could see as the sun moves west, in fact you do see
the difference. And so you could also see, you know, the peaking, you know, as these
ones facing more straight up. It's peaking, you know, closer to the middle of the day
whereas this one is you know, tilted to the west and it's peaking later on in the day.
So, you could see the effect of sun angle right here. And, you know, there is, you know,
between let's say, 2000 and 2600, you know, there is a difference that it makes in your
production but it's not like, you know, if your 20 degrees out, you go down to half power
anything like that. >> Most of you guys are talking about maintenance.
How often do you clean your panels and do you have to scrub it or you just hose it down?
>> MURVEIT: So, I don't think--quite honestly I mean I've only had them for four months
and quite honestly I don't think that there is a big effect on that yet. You know, I've
heard that Google made the decision that it's actually cheaper not to scrub the panels.
That, you know, the loss in production that they get, from whatever, you know, lines up
on those panels up there is minor compared to the cost of hiring people to go up there
and clean it somehow. So, I think Google made that decision. You know, for me I'm pretty
sure that when, you know, in the fall, when we get all sorts of leaves and stuff like
that. It might be worth my while to go up there. You know, I got the trees to produce
those leaves and perhaps Google doesn't. But, I think in general it isn't--and it--I have,
you know, being a new solar owner I showed to you that slide where I, you know, I was
intent on keeping them clean. And I went up there sure enough I got this big gain in performance.
And then a half hour later the gain was gone and like I said that was all cooling...
>> TALKIN: Let me just say that the 480 [INDISTINCT] array that I've got in my country place has
never been cleaned. It's that slight pitch that you saw and just the rain is enough to
wash off the pollen and stuff. >> Talking about issues related to tracking
systems that will track the sun? >> NEWICK: Yeah. That's more important if
you're in the off grid application, you know, the latitudes around here. It's certainly
a waste of money but we get, you know, maybe 25% more power but you got moving parts something
to break down. And you could really--I recommend people to spend that extra money for the tracker
to put in more solar panels. You're much better off. It's maintenance free. Once you put in
the panels once, you forget about them. How often should we clean them? You know, some
people once or twice a year in the summer in California, just hose them down. That's
what we recommend. You do get, you know, 5% more if it really does, we've seen the 10%
when it's very best dusty locally. So, trackers are a waste of a--a waste in my personal opinion.
We've installed them before in the past, they're really good if you're in northern climates
you're trying to optimize winter sun but in the summer here. Maybe winter's time is not
really that financially, you know, beneficial. The rains will drop down in the summer.
>> TALKIN: I completely agree with Kurt. Just spend the extra money on more panels.
>> NEWICK: We have another question there. Go ahead.
>> Yes. You mentioned cooling--the cooling effect, in fact that you had a surge in production.
Okay. Has there been any research into looking at you know, setting up maybe sprinklers systems
or cooling systems? >> MURVEIT: Yes, funny that you ask. I won't
answer the question directly. I'll let Kurt take that one up. They also sell pool heaters--I
mean pool warmers, right? That's their business, in fact. I guess there on the business originally
doing that. And so, you know, I suggested that, "Hey make this combination pool warmer,
solar system, you know. And then the pool will cool off your panels and it's a win-win
and Kurt and Bruce both came back and said are you crazy, you know, mix water with high
voltage--high power electricity. You know what a terrible idea. But, I think there actually
are ideas like that but... Go ahead. >> NEWICK: Say, what's the question again?
I'm sorry. I was... >> Cooling down your panels [INDISTINCT]...
>> NEWICK: Cooling down. Yeah. There's a--there's a--that's done, you know, some--there's a
gas station that does that. You know every 20 minutes it comes on. In the Central Valley,
they did get a performance because water is free over there. That's one of the benefits
of solar that requires no water. So, if you do, you know, hose them down, it goes up temporarily
but it's a very minor thing and most people don't do that. And no, I don't know any product
out there that--you just put some sprinklers up there if you want to do that. But, you
know, you want to be careful that you don't thermally shock your panels because it gets
very hot maybe a 150 degrees in the afternoon. If you sprayed them with water in the afternoon,
that will cause them to cool down rapidly, you know, cause expansion and contraction
and over time that may weaken some of the wiring in them. So, I don't know if you really
gain anything, you're just going to--maybe cause problems in the long run by cycling
those thermal expansion and contractions more. >> All right. Thank you very much.