PV potential by US state

[ggirod]

Re: PV potential by US state

A reality check for pot-heads who think they can store food at 39F to 45F:

If you keep your fridge at "39F (+4C) to 45F (+7.5C)", you will end-up with food poisoning because bacteria will multiply just enough at these temperatures to create toxins. You would end-up dead. :rolleyes::eek::rolleyes::p:rolleyes::eek:

Lest people get misinformed, here is what the USDA has to say about refrigerator temperatures -- below 40F. I checked and it appears that milk storage is now less than 40F also. I prefer it closer to freezing for a safety margin and efficient refrigerators can readily keep food at whichever temperature you choose and engineer for. Solar refrigerators do not quit working below 40 degrees. Period.

In fact, chest freezers with thermostats modified to work in the just above freezing range make fantastic efficient and inexpensive refrigerators for those on a budget who also have a refrigerator thermometer to be sure how it is doing.

[Starving Steve]

Re: PV potential by US state

By the way, pot-heads, if you are thinking of freezing foods, your freezer had better be set as far below freezing as is mechanically possible in order to cut the risk of food poisoning. Maybe set your freezer at -22F (-30C), and not at +30F ( -1C).

Think of this life-style dilema like this: "Whatever you save in your electric bill (by living off of the grid and conserving power) would be pissed-away in your funeral expenses after food poisoning." :rolleyes::rolleyes:

[we_are_toast]

Re: PV potential by US state

... Local grid power from our coop is $0.10 USD per kWhr (we don't use TOD basis), so I should break even in about 34 years at the present rate. Probably won't live that long, honestly.

The average price of electricity in Georga in 1990 was $.065, in 2009 it is $.1089. That's a 67% increase in the last 19 years.
http://www.eia.doe.gov/cneaf/electri...ales_tabs.html

If you subscribe to iTulips general thesis of dollar devaluation and Peak Cheap Oil, I think you can safely assume the rate will increase considerably faster in the next 19 years. And don't forget to add in all those little taxes and fees at the bottom of your bill. I think if you recalculate your payback period with projected increases in the price of electricity you'll find that the payback period is substantially lower.

Moonclifs approach of substituting solar panels for roofing materials is another way of reducing the overall costs of the system. A few minor changes in building codes concerning orientation and pitch of roofs and you get an increase in overall efficiency and a subsequent decrease in $/watt costs.

Although Residential solar/wind can be economically justified in many cases, the real economic advantages will be for medium size commercial producers of solar and wind energy. On many farms in the midwest it's more profitable for a farmer to lease acres to a wind generating company than to plant it in corn. And that advantage will only increase as the input costs of farming continue to increase. As the subsidies for fossil fuels are phased out and the subsidies for Alt-E increased, the economics of Alt-E only get better and better.

If you keep your fridge at "39F (+4C) to 45F (+7.5C)", you will end-up with food poisoning because bacteria will multiply just enough at these temperatures to create toxins. You would end-up dead. :rolleyes::eek::rolleyes::p:rolleyes::eek: It's your choice: a few cents more per day keeping food COLD at (or under) 34F (+1C)...

The state of Wisconsin requires milk to be stored at 33F-41F. I think we'll survive.;)

[fallout]

Re: PV potential by US state

A lot has changed in this area in recent years. When I was younger, I worked many years in crappy dead-end food service jobs (fast food, etc) here in the southeast US. At that time, it was normal for the walk-in reefer to be at 43-45 degrees F, and health inspectors wouldn't even ding the restaurant for a reefer unless it was over 45 degrees. Employees would sometimes go in there and stand just to cool off.

A chest freezer makes an effective and efficient freezer for two main reasons.
1) They're meant to operate at lower temperatures than refrigerators, and hence have better insulation.
2) Cold air settles, rapidly. On a front-opening fridge, every time you open it all the cold air pours out onto the floor. Not so with a top-opening model.
It IS considerably more inconvenient to use, however, due to the need to stack items vertically, plus lots of bending over to access contents....something to keep in mind when you get older.

A "brewers thermostat" is all that is required, they cost about $60 and sit inline between the wall outlet and the freezer plug, basically turning the freezer on and off when tripped. Temperature is adjustable, and are often made by reputable companies such as Johnson Controls or Honeywell.

[fallout]

Re: PV potential by US state

You won't get an argument from me regarding likely future energy cost increases, obviously I sprung for PV despite the present ROI. :p
That said, for Average Joe such will remain a tough sell until the 2x4 hits them in the head.

As an aside, it costs me $20 a month for electricity even if I use none, nada, zero.....that's the amount the coop charges to bill you and have a meter (i.e. residential service charge).
Damned if you do, damned if you don't.....

[govtraksam]

Re: PV potential by US state

Yes, and you can then get used to no electric power for 66 to 75% of the day and since any kind of worth while jobs will be long gone you can spend your time looking for berries and nuts to live off of. If not for government tax credits, grants and mandates none of this nonsense would even be discussed. I drove thru N. Dakota, Montana and Wyoming last year, I saw wind farms with hundreds of wind turbines. Problem was, not many were turning. You can't have a viable modern economy without reliable base load generation. It's nice to dream that this or that technology is going to save the day, but unless you really understand the massive amounts of electricity that we use compared to what is available with wind and solar using currently available technology, you will delude yourself by believing that wind and solar in their present form are the answer. It's kind of like flying cars that have been touted forever, it ain't going to happen in the real world.

[VIT]

Re: PV potential by US state

Some time ago I did some math to estimate what is the area needed to cover by solar energy for today's oil+gas+coal consumption expressed in btu.

I used conservative approach to get the smallest area:
- solar flux conversion efficiency, average 0.19 (including bad days, dust, misalignment and etc)
- area efficiency 0.6
- Egypt solar flux


I ended up with the territory equal to France needed to be covered by PV.

Is it possible ? Probably yes, is it really good idea, not so sure. Think about this in broader sense, when we switched from coal to oil did we just match the consumption or we increased it. Now we are struggling to make the system which would only match the current consumption. What about 3 or 10 times more energy supply then we use today. The recycling will be more and more important and this will require tons of additional energy as well.

[mooncliff]

Re: PV potential by US state

I've tried to download the report a few times from here:

http://www.newrules.org/sites/newrul...files/ESRS.pdf

...but no report. I'm out of the office this week so maybe it's my connection? I've several comments but I need to review the report. Is it available at another link by now?

When I click on the link, it works, so maybe there is just a temporary problem? You might need to sign up, but I don't think so.

[santafe2]

Re: PV potential by US state

This is solid analysis by c1ue.
I'm old, I was actually around for PV installations in the late 1970's and early 1980's. Costs on a per-kW basis haven't really changed much in 30 years, adjusted for inflation, despite year-after-year promises of technological breakthroughs and economies of scale. The small and incremental gains in efficiency have been offset by higher material costs, manufacturing costs, labor costs, and transportation costs.

Let's talk about reality for "average 'murkans", no pie in the sky theoretical possibilities in a laboratory setting.
I live in south Georgia, full on deep south, with 5.5 hours of "full sun" equivalent a day on average (straight off the insolation map).
Last year I had a typical run of the mill 2.1kW grid-tied system installed on the southwest facing portion of my 27 degree pitch standing seam metal roof (thus avoiding rack and mount costs). Equipment costs for a Fronius inverter, clamps, 12 panels (manufactured in British Columbia, incidentally), and associated hardware ran $10k (delivered), with professional turn-key installation from a licensed electrician another $6k. I applied and received state and federal tax breaks amounting to $6k. The system provides about 1350kw peak nominal power in use, or roughly 7-9kWhrs per day (significantly less on cloudy days, naturally). Call it 8kWhrs being generous. This represents about 1/4th of our annual usage. Local grid power from our coop is $0.10 USD per kWhr (we don't use TOD basis), so I should break even in about 34 years at the present rate. Probably won't live that long, honestly.

Note that we were the very first residential PV installation in our electric company's half-million person service area ever (bleeding edge early adopter), resulting in no end of hurdles and headaches initially (from getting a two-way meter to even getting them to continue to provide service to us, despite clear state law covering the matter).

Now don't get me wrong, I still have faith in distributed micro-power generation via photovoltaics, but at present this simply does not make sense for most people, nor can they afford it. Until that changes noticeably and measurably, PV will remain an expensive toy.

Thanks for the on-the-ground report. I did a few quick calcs for your approximate location and NREL says your output numbers are right where they should be given their 40 year average insolation numbers. And I've no issue with your 34 year calculation, given NPV, it's probably low.

The issue we see in Georgia, (and several other states), is that the cost of electricity is low and there are little to no local incentives so it's not possible for PV to compete with fossil fuels. As you noted, it's unlikely to pay back in your life time.

That said, there are states and local utilities that provide up to 50% cost off-sets in the form of tax credits, up front rebates and/or renewable energy credits. These credits are available in addition to the Federal tax credit of 30%. Some of these locations have kWh energy costs double your cost and a few have costs 4X your cost. The payback calculation in the US is location specific.

As for PV costing about the same today as it did in 1979, that's incorrect. It's less than 10% in inflation adjusted terms and that's not counting all of the extra parts one needed to complete the average system then, (batteries, controllers, etc.). Almost all systems ran off the grid as there were no commerically available grid-tied inverters. In 1979 a solar panel cost $18-20 a watt and had dropped over 50% in the half decade prior to that time. Today an average solar panel costs under $3 a watt and in inflation adjusted terms, about $1 a watt.

[mooncliff]

Re: PV potential by US state

Some time ago I did some math to estimate what is the area needed to cover by solar energy for today's oil+gas+coal consumption expressed in btu.

I used conservative approach to get the smallest area:
- solar flux conversion efficiency, average 0.19 (including bad days, dust, misalignment and etc)
- area efficiency 0.6
- Egypt solar flux


I ended up with the territory equal to France needed to be covered by PV.

Is it possible ? Probably yes, is it really good idea, not so sure. Think about this in broader sense, when we switched from coal to oil did we just match the consumption or we increased it. Now we are struggling to make the system which would only match the current consumption. What about 3 or 10 times more energy supply then we use today. The recycling will be more and more important and this will require tons of additional energy as well.

If you mean photovoltaics, they need not actually take up new land area.

Solyndra is targeting commercial buildings with flat roofs.

I have seen entire walls of shopping malls in Japan, tens of thousands of square feet, covered with photovoltaics (vertical, so less dust and no snow accumulation).

My roof on Oahu (23 degrees N) is 2,000 square feet. 100 square feet of photovoltaics should more than cancel my electric bill, and depending on how the feed-in tariff works out, I might install 400 square feet. That is a small fraction of the roof space available. In addition, I intend to install bifacial panels standing upright, so they will actually take up only a few dozen square feet of actual roof. The roof is elastomeric and white, so more light, up to about double, will hit the panels, no tracking or lenses necessary.

There are reports some parts of Australia are proposing 60 cents per kilowatt-hour for the feed in tariff!
http://alohaanalytics.blogspot.com/2...h-feed-in.html

[dbarberic]

Re: PV potential by US state

Living in MA the problem I have with PV is that electricity usage accounts for less than 1/4 of our total energy bill since we use barely any AC (a window unit for a couple of weeks a year) and we have gas heating. Of course generating electric from PV and then using an electric heater makes absolutely no sense at all from an overall efficiency point of view : better to improve the passive solar gain of your house with a south facing skylight.

This makes the ROI for PV a bit of a loser. The low hanging fruit for reducing our electric bill / footprint was switching to CFLs and replacing the fridge (which we will only do when the current one dies). We also switched our electric provide to one whose primary source is wind energy.

If we lived in a warmer climate where AC was a larger proportion of our energy usage I think PV would make a lot of sense. If we moved to AZ I'd have a PV panel on the roof within the first 12 months.

I think solar hot water has more potential nationwide as it has a much higher efficiency, and hot water is something that we all use, probably in similar amounts (I'm not going to question the personal hygene of any regions of the US ;) )

I do like the idea of decentralized power generation, though.

Living in NE Ohio, I've come to similar conclusions.

I've always wanted to install a PV system on my house, but it does not turn out to be economical. Except for a few summer months, our electric usage is not very high and at 0.12 cents a KWH, it would take forever to payback.

Heating is the largest consumer of energy here and I'd get more of a payback adding insulation and switching my NG furnace to an Energy Star model.

[we_are_toast]

Re: PV potential by US state

Living in NE Ohio, I've come to similar conclusions.

I've always wanted to install a PV system on my house, but it does not turn out to be economical. Except for a few summer months, our electric usage is not very high and at 0.12 cents a KWH, it would take forever to payback.

Heating is the largest consumer of energy here and I'd get more of a payback adding insulation and switching my NG furnace to an Energy Star model.

I think you've made a very important point. When you get down to the residential level, it's critical to look at your local conditions and needs. I think you've nailed it by going down the conservation road, given your location. PV and wind doesn't work for everyone, but there are many other approaches to "insulating" yourself from the coming rise in fossil fuel prices.

Just a couple things to think about;

Insulating hot water pipes and heaters usually has a rapid payback period.

Geothermal heat pumps may be a possible alternative if you need to replace your furnace. You really need to shop around if you consider one of these systems. Prices and quality can vary tremendously from dealer to dealer and the systems are pricey to begin with.

[lurker]

Re: PV potential by US state

Living in NE Ohio, I've come to similar conclusions.

I've always wanted to install a PV system on my house, but it does not turn out to be economical. Except for a few summer months, our electric usage is not very high and at 0.12 cents a KWH, it would take forever to payback.

Heating is the largest consumer of energy here and I'd get more of a payback adding insulation and switching my NG furnace to an Energy Star model.

ROI for a new furnace/boiler can be tricky also. We have an ancient 70% efficient (auditor's estimate) gas boiler. So we could replace it and realistically get to low 90s (boilers don't go much above this). However when I spoke with the NSTAR maintenance engineer he did admit that the condensing boilers with fan assisted flue and electronic ignition do tend to be less reliable, and that they may have a service life of less than 20 years (compared with 50-100 yrs for our old cast iron monster).

Even with last year's high gas prices our total heating bill was under $2000 for the year. So if we take 20% off that we save about $400 a year. Then the cost of a new boiler plus new flue work and plumbing would leave little change from $10,000 (again NSTAR estimate).

This leaves an ROI of 20 years, though I'll accept gas prices will likely rise above inflation over the coming years, so let's call it 10 yrs. I think I'll add more insulation, buy some more polyurethane foam cans (100 yr old house: biggest problem is air infiltration) and keep on putting up that 3M window film on windows we don't HAVE to open all winter.

In the end we took the $10,000 cash we'd put aside for energy efficiency and put it into paying off the mortgage.

[VIT]

Re: PV potential by US state

If you mean photovoltaics, they need not actually take up new land area.

Solyndra is targeting commercial buildings with flat roofs.

I have seen entire walls of shopping malls in Japan, tens of thousands of square feet, covered with photovoltaics (vertical, so less dust and no snow accumulation).

My roof on Oahu (23 degrees N) is 2,000 square feet. 100 square feet of photovoltaics should more than cancel my electric bill, and depending on how the feed-in tariff works out, I might install 400 square feet. That is a small fraction of the roof space available. In addition, I intend to install bifacial panels standing upright, so they will actually take up only a few dozen square feet of actual roof. The roof is elastomeric and white, so more light, up to about double, will hit the panels, no tracking or lenses necessary.

There are reports some parts of Australia are proposing 60 cents per kilowatt-hour for the feed in tariff!
http://alohaanalytics.blogspot.com/2...h-feed-in.html

Do you use your roof to fill the tank of your car ?
Do you use it to heat/cook ?

Electricity is only 24% of total energy consumption.

[mooncliff]

Re: PV potential by US state

Do you use your roof to fill the tank of your car ?
Do you use it to heat/cook ?

Electricity is only 24% of total energy consumption.

Yes, but no one thing is going to solve all the problems. It will be a little here and a little there, but in the end, it can wind up making fossil fuel consumption go way down.

Most houses in Hawaii are electric only, so the stoves are electric.
The elastomeric roof means much less need for air conditioning or none.
The solar water heater means energy used for heating water is near zero.
Even now, a $15,000 photovoltaic system would more than cancel my electric bill. I am just waiting so see the details of the feed-in tariff.
Doing these three simple things makes the house use zero energy.
And this was free because the elastomeric roof saved $13,000 over a conventional reroof, and the solar water heater has saved $30,000 over 30 years... so far.

The next car we get will be electric, in say 5 years, so then the gasoline we use will fall to about zero. Better yet, we are supposed to have half of a light rail system in 3 years and the full system in 9 years. If that works, I will forgo the car altogether.

I am having a deck constructed so we can go back to growing food the way we used to when I was little... only this time, it is high tech with aluminized shade cloth, which I have tested for several years, and it works great. The plants are about double in size because they get bright diffuse light all day and do not get burned.