Guest essay by Chris Yakymyshyn
Vermonter Bill McKibben was recently quoted in Salon Magazine:
“The roof of my house is covered in solar panels. When I’m home, I’m a pretty green fellow. But I know that that’s not actually going to solve the problem.”
This is a very interesting comment. He had solar panels installed on his home, even though he knew it would not ‘solve’ the CO2 problem.
One goal of installing solar PV is to reduce CO2 emissions associated with generating electricity. Ideally, this would be achieved at a cost that is less than the social costs of CO2 emissions, estimated by the EPA to be somewhere between $12 and $117 per ton in 2015. To minimize the cost of avoided CO2 emissions, ideally a residential solar PV system replaces utility energy that is supplied by burning coal, since coal produces the highest CO2 emissions per kilowatt-hour. Likewise, adding solar panels in a location that already receives 100% carbon-free electricity will result in an infinite cost per ton of avoided CO2, since no CO2 emissions will be avoided. The reality at your wall outlet will lie somewhere between these two limits.
I decided to calculate how much it costs to reduce one ton of CO2 emissions by installing a residential solar PV system in Vermont. I then repeated the calculation in every other U.S. state and Canadian province or territory. This estimate assumes that electricity generated within a state, territory or province is consumed there, and that electricity imports constitute a small percentage of total electricity consumed within that state, province or territory.
The first step is to figure out roughly what percentage of today’s wall-plug power is provided by coal, natural gas, nuclear, wind, solar, hydro, geothermal, biomass, etc. The Energy Information Agency (EIA) tabulates, by year and by state, the total amount of electrical energy (in Megawatt Hours, or MWhr) delivered by each type of generating source. For the most recent year available (2011) in each state, the utility and IPP (Independent Power Producer) electrical energy generated by CO2 emitters (coal, natural gas, petroleum liquids) and non-CO2 emitters (nuclear, wind, solar, hydroelectric, geothermal and biomass) was extracted, with the assumption that biomass was carbon neutral. The ratio of fossil fuel to total electrical energy produced was then calculated for each state in 2011. The results ranged from 0.14% fossil electricity in Vermont, to 98.7% fossil electricity in Delaware.
The same tabulation was performed for Canadian provinces and territories using 2011 data from Statistics Canada. In Canada the results covered the entire range, from essentially 0% fossil electricity in Prince Edward Island up to 100% fossil electricity in Nunavut.
Next, the CO2 emissions per MWhr were calculated using the following emissions estimates: 1.4 tons/MWhr for coal, 1.0 tons/MWhr for fossil liquids, and 0.47 tons/MWhr for natural gas. The total CO2 emissions were estimated by multiplying the energy in MWhr produced from each source, by the CO2 emissions per MWhr for each source. The resulting CO2 emissions in 2011 ranged from <0.001 million tons CO2 in Prince Edward Island, 0.008 million tons in Vermont, up to 279 million tons in Texas.
The average CO2 emissions associated with electricity generation in each state, province or territory in 2011 was then calculated by dividing the total CO2 emissions by the total amount of energy generated. The resulting averages ranged from <0.001 tons CO2 per MWhr in Prince Edward Island, 0.001 tons CO2 per MWhr in Vermont, 0.567 tons CO2 per MWhr in Nevada, to 1.36 tons CO2 per MWhr (almost 100% coal) in West Virginia.
The amount of solar energy generated by a solar PV residential system was next estimated. The annual averaged hours per day of full sun for a South-facing fixed solar array tilted at latitude was extracted from the National Renewable Energy Labs (NREL) Renewable Resource Data Center. The values ranged from a low of 2.5 hrs/day in Yukon Territory up to 6.5 hrs/day in Nevada and Arizona. Assuming a 10 kW(AC) system with a 20 year service life and no aging, the total energy delivered by the rooftop solar PV system was estimated in Nevada to be (6.5 hrs/day)*(365 days/yr)*(20 yrs)*(10 kW(AC)*(0.001 MWhr/kWhr) = 475 MWhr of electricity. All of the generated electricity was assumed to be used somewhere in Nevada. This calculation was repeated for every state, province and territory.
The cost of the residential solar PV system was needed next. A recent article at Solar Panels Review gave 2013 price estimates for a contractor-installed system using several panel choices. The average unsubsidized cost was $5.57/Watt AC, or $55,700 for a 10 kWAC system. This unsubsidized cost is assumed to be the same everywhere.
The cost of CO2 emissions avoided using residential solar PV can now be estimated. The cost per ton CO2 avoided is given by the solar PV system cost divided by the total CO2 tonnage avoided over the 20-year life of the system. For example, using the previous estimates for Nevada, the avoided CO2 emissions cost is given by ($55,700)/(475 MWhr*0.567 tons CO2 per MWhr) = $207/ton CO2. This calculation was repeated for every state, province and territory and, as shown in Figure 1, plotted versus the fraction of generation that is free of CO2 emissions.
First, notice that the vertical axis is a logarithmic scale, ranging from $1/ton CO2 (well above the 5 cents/ton that traders at the now-defunct Chicago Climate Exchange determined was an appropriate price), up to $10,000,000 per ton CO2. Several horizontal lines indicate the California carbon exchange price of about $12/ton CO2 and one EPA estimate of around $60/ton CO2. A vertical line marks one widely discussed goal of 80% CO2-free electricity generation.
Note how the use of residential solar rapidly escalates the cost of avoiding CO2 emissions as the power grid moves towards a ‘low-carb’ diet. Also note that even in ‘high-carb’ states at the left side of the graph, residential solar PV is an expensive way to avoid CO2 emissions associated with electricity generation, never breaking below $100/ton CO2. Substituting DOE’s 2020 SunShot goal of $1.50/Watt installed cost for a residential system shifts the curve down, but retains the highly coveted hockey stick shape J.
So, Bill McKibben’s solar panels in Vermont are indeed avoiding CO2 emissions in Vermont (one of the data points at the far right side of Figure 1), at a cost of around $155,000 per ton CO2. This is equivalent to paying a carbon tax of $2.00 for one teaspoon of gasoline.
Figure 1- Semi-log graph showing the cost of avoiding one ton of CO2 emissions using residential solar PV, province or territory, as a function of the carbon content at the wall outlet. Several U.S. states and Canadian provinces are indicated. The two horizontal lines represent two official estimates of the social cost of carbon dioxide emissions.
References-
Salon magazine article-
http://www.salon.com/2013/09/15/bill_mckibben_being_green_wont_solve_the_problem/
Solar insolation data from NREL-
http://rredc.nrel.gov/solar/old_data/nsrdb/1961-1990/redbook/sum2/state.html
Electricity production in the U.S.-
http://www.eia.gov/electricity/data/state/
Electricity production in Canada-
Solar PV system costs-
http://solar-panels-review.toptenreviews.com/
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An argument usually brought forward is “give technology time”… (as if it already didn’t have enough time…). People dream of “cheap” solar with solar panels that cost almost nothing per sq.ft. However, they never realise that even if the panels were free, there is always a maximum efficiency and a limited quantity of energy from the sun. AND the system costs (batteries, inverters, cost of installation,etc) also represent a large cost of the system.
It would be great if you added to your analysis the most optimistic forecast for lower prices of solar panels. My hunch is that despite a solar panel cost of zero $/sq ft, it would still be a loosing proposition.
Mike Hebb says:
October 22, 2013 at 11:00 am
“The amount a customer receives is based on the value of the energy that GMP charges the customer, plus an additional 6 cents per kilowatt-hour generated by solar arrays.”
Ah, this explains those large solar arrays visible on the fine drive up RT. 89. No limit on the transfer payment.
RACookPE1978 says:
October 22, 2013 at 11:29 am
There are no more available anywhere in the country sites for “new” or expanded pumped storage sites capable of storing any portion of today’s power needs.
================
Mostly, I think you might be right, but there is one exception on the relatively well watered East Coast of North America that looks like it might be feasible for pumped storage of a fair amount of power. That would be pumping water from Lake Ontario up 100 meters over the Niagara Escarpment to Lake Erie or Lake Huron. I did a rough calculation a few months ago that said that it might be possible to store a day’s electric power for the East Coast of North America without changing the lake levels by more than about 4 inches. Lake level changes of a few inches might not result in too many successful (and actually meritorious) lawsuits.
It’d be a VERY costly project. The permits alone would take years if not decades. The lawsuits …
‘That would be pumping water from Lake Ontario up 100 meters over the Niagara Escarpment to Lake Erie or Lake Huron. ‘
Why do that, spending the money and energy when rain/snow does it for us? You’d still have to build the underground tunnel (The new one costs just over a billion) anyway to pump up to Erie, so why not just let it run down from Erie in the first place?
Madness clearly dominates the energy discussion.
“The average unsubsidized cost was $5.57/Watt AC, or $55,700 for a 10 kWAC system. ”
GET OFF THIS PLANET!!!
“Was” is the operative word. Simply look on the Chinese selling sites, 1WAC is $0.5c to $3 max for a “professional” but not ripped off home fitted installation. Panels themselves are down to $0.40/W
As it stood in the UK three years ago, (after the stolen carbon tax money is returned). Was an easy 20%~30% payback for a home fitted system. That’s 3~5 yr’s before it becomes back pocket money!
There is no better investment. Millionaires don’t do it because they are green. They do it because they are clever.
Removing all carbon tax rebates and going alone, avoiding the profiteers still pays back much, much faster than any tax free pension scheme.
That’s only the electric. On hot water I installed a vacuum tube panel in the summer of 2007 in the dark and grim North of England. The cost after I installed it totalled £500. The payback alone on that was 18 months. Another £2K ($6) in my pocket to this date.
Then there are my space heating panels which keep knocking off my central heating… 🙂
And my Electric car which returns (assuming no Solar or night rate) on money >200 mpg (UK).
I’ve not done this because I’m a Gore-botted carbo-nazi. CO2 grows the food on my plate.
I love my money, revere being independent, cannot beat the easy money. Hate anyone who tries to control or own me via contract and doing my bit to stymy the oncoming further oil wars.
Andyj says:
“I’ve not done this because I’m a Gore-botted carbo-nazi. CO2 grows the food on my plate.”
Good for you, Andy. I for one would never criticize anyone for taking free money. It is the free money givers who earn my wrath. They have no right to give away my tax money like that, and those who blithely excuse that theft by their enabling phrases, such as the “…social cost of carbon is $38,000” are excusing the confiscation of our money based on the outright lie that “carbon” is a problem.
CO2 is not a problem, and I challenge anyone here [lookin’ at jai mitchell] to show that the rise in CO2 is anything but beneficial.
Andyj says:
“As it stood in the UK three years ago, (after the stolen carbon tax money is returned). Was an easy 20%~30% payback for a home fitted system. That’s 3~5 yr’s before it becomes back pocket money!
There is no better investment. Millionaires don’t do it because they are green. ”
And is didnt bother you that that “easy money’ was throwing millions of Brits into energy poverty, FORCED to fill your back pocket, having to choose between keeping the lights on, or feeding their kids.
I say again, madness dominates.
Not only can’t a solar panel ever generate as much power as it took to create it but most solar panels are made in China using coal fired electric generation. It is really ironic because if PV was practical there would be no better or more natural place to use it then a PV production facility. After all they could get the panels for cost.
GoneWithTheWind says:
October 22, 2013 at 3:59 pm
Not only can’t a solar panel ever generate as much power as it took to create it…
So China are selling them to the whole world at a loss? riiight!
In the ’70’s this was true. Panels were barely 5% efficient, hand made at great heat. Easily broken and used for high value items like satellites.
Now they literally print the substrate onto glass. The av. 20% efficient panel at top prices is $0.8/W. The warranty is around 25 years! The UK averages around 10 Mj / m^2 per day.
So I absolutely disagree.
Mr. Wakefield,
I can only half agree with you.
My yearly cash income is under £11K and I live very, very nicely thank you 🙂 Please re-assess what really makes poverty..
A situation at the age of 18 forced me to get a mortgage. So my Dad was guarantor, (never had to pay a thing). I was on £23/week as an apprentice; soon after I moved in £28/wk (1979).
The first thing I did was sort out the freezing upstairs (ceiling!). Thank you Horwich tip!
Found huge drafts ran between the floorboards so cemented them up. Fixed the windows, doors, all sorts of things. Damp proofing cost me but well spent. Barely cost anything to put right for the gains. When I sold that property, I made a killing, moved in with sis and bought a Honda car before the £ plummeted and made Jap cars very expensive. Bought this house around ’89(?), months before house prices almost doubled around here. Was soo tempted to cash in, again.
Self enforced poverty existed in my first house for the prior 100 years. All the prior families suffered badly. If they got their finger out life would of been far nicer. Going to blame me for that too?
Don’t buy into what you hate when the blames are obvious.
Imagine if all the products you enjoy consuming (eat, smoke, drink) were guaranteed not to cause cancer and at the same time fulfil all of your cravings … would you be willing to pay 100% or 200% more for them to ensure a longer life?
I was surprised to find on a recent trip to China that their major wind electricity generating area in the midwest has the windmills shut down in winter when the winds are the strongest and most consistent.
This is done because the electricity is not needed. The coal-fired power plants that are connected to the home heating systems are running flat out to keep the home fires burning, so to speak. Combined heat and power (CHP) is very efficient in terms of the whole system. The temperature of rejected heat is on the order of 80 C. Homes are not equipped to be heated with electricity so the windmills are turned off for the duration.
That is the sort of thing that is not obvious to promoters who make acultural interventions.
Windpower is a clean, renewable and sustainable resource……………as long as it kills someone else. As long as the crime is out of sight and out of mind then it’s OK. As long as we feel green then we are green. That is the ticket.
Why wasn’t the area powered by windpower instead of fossil fuels?
lol@Jimbo
You should of seen my local coal town 60 years ago. This is not pollution created, it is pollution released through cheap practices.
Rare Earths are not rare, can be easily removed from sea water… But who cares? the major supplier has cheaper labour.
I wish people on here stop being so myopic or others will have a field day.
Whole swathes of the US, AUS and Canada have succumbed the the ills of huge scale coal mining. Same for mass pollution from oil in Africa. The oil magnates don’t care. They know their workers leave work the same colour as they walked in.
Hundreds of thousands of innocent people have been crippled and killed because of oil alone:-
Iraqis, Afghans (supply pipes), Syria, Libya, Chechnya…. etc. etc.
Untaxing yourselves off liquid/gaseous fossils ought to be a no-brainer.
China is making and selling cheap just like Saudi. While our Gov’ts are granting eminent domain of your properties to pay off the debts.
“Whole swathes of the US, AUS and Canada have succumbed the the ills of huge scale coal mining. Same for mass pollution from oil in Africa. The oil magnates don’t care. They know their workers leave work the same colour as they walked in.”
There is no Utopia, there never will be. Compared to how people lived, worked and died in the historic past before fossil fuels freed us, we are the closest we will ever get to Utopia right now. Thanks to fossil fuels. Wind and solar will never replace fossil fuels and maintain this living standards. The world cannot prosper on expensive energy, and these “green” sources will never be cheep source of power. Why? The Energy Trap.
lol, I’m in utopia because my house and water is warmed most of the year for free and the electric meter runs backwards half the time.
As I’ve said before, as an investment they prove themselves to be a no-brainer. Stop guessing, do the maths!
Andyj takes a box to the footy and skites how he can see perfectly so you low heeled dumbclucks should get with program. Cute Andy but most here understand the ‘fallacy of composition’ from Econ101 so you might look it up.
Very observa(not) of you.
Are all you people still refusing to put insulation in your attic? lol
I have already stated my yearly cash income is under £11K. Personal time and effort create incredible investments.
Econ101.. WTF?? I don’t use models nor care for opinions of others who also suffer from ‘fallacy of composition’ when actual data preserves the contents of my back pocket and supplies the facts.
No good tilting at my windmill. I don’t have one.
Andyj, would you honestly purchase a storage-less car that is beautifully covered in flexible solar collection material and goes like a Tesla in maximum bright sunshine but its performance drops off commensurately with declining sunlight until it won’t run on moonlight? If your answer is yes I have this bridge to sell you, but please spare me the wonders of your particular bridge for sale.
jrwakefield,
I cannot ever be a net loser.
Being a Libertarian myself I’m totally behind removing all Gov’t interference. They should be responsible for base infrastructure only. Businesses ought to be in competition with them and not suck off each other, that gets stupidly expensive, (profiteering) and destroys value for money. It’s also a base principle of Fascism.
And to allay your self informed misinformation because you did not read my earlier posts properly I do not want nor use any Gov’t “help” whatsoever. However, buying the car and accepting to have an EVSE installed for free was not turned own. I pay taxes too.
The reasons are very simple.
1. Having anything assembled & signed off needs a guy who rips everyone off due to easy Gov’t money.
2. The electric company will alter my meter and change the rates. Will not allow my meter to read less than zero at any time, no matter how much they take. And the inverters they fit are “anti-islanding”.
3.The contracts suck.
4. I imported these items myself apart from a local supplier of the vacuum tube panels (£500 fitted by me, paid for itself in 18 months, no financial help.) and relevant building supplies for sundry items.
====================================
Observa. What’s this lunacy you are on about with “storage less” cars? You want cheap and easy energy storage? A written off Nissan Leaf sold for £2,850 a few days ago. That has a >20KWH pack of 350~393V. The cycle life as a “load balancer” (Go read up). It will outlast you.
The Voltage is easy meat for a nice inverter.
Stop ass-u-me’ing. It’s a sad reflection on your psychology.
Here’s a simple fact.
25 years ago I bought a light for the living room. Nice light, didn’t cost too much maybe £15 at the time. Takes 3x 60W bulbs and it was on 10 hours/day (yearly average) for 20 years. Here electric is £0.15/KWH. That’s almost £2K I worked for 2 months off my life for the light! The past several years had 20W of CFL bulbs.
The bill is effectively 11% Rather £10/year than £200 eh?
Confusing simple common sense for a carbo-nazi is seriously stretching the boundaries of normalcy.
No problem with your solar hot water collector and its storage system as long as you don’t ask me to subsidise it of course.
“As I’ve said before, as an investment they prove themselves to be a no-brainer. Stop guessing, do the maths!”
I’m on the Ontario Progressive Conservative Energy Policy Advisory Committee. We recently released a white paper on what we would do after the next election and we get into government. In that paper we outline a pricing system for the future. No FIT, it’s over. But what to do with current FIT contracts? Simple. Every wind and solar producer will have to get subscribers. That is, those people who feel guilty of their ecological footprint can sign up to get power from wind and solar, and pay the full price for them. Wind/solar producers will only be able to dump into the grid that power for which subscribers are willing to buy.
This will kill all existing FIT producers. So no, absolutely not is it an investment. It only appears to be an investment from your perspective because of the generous FIT pricing which forces people to pay. Kill the FIT and you’re stuck with panels for which you cannot get payments on.
The system is going to collapse, and you will be the net loser.
“Are all you people still refusing to put insulation in your attic? lol”
Tell you what, I’ll add more insulation, and you will pay for it. That’s what FIT is. Other people are paying for your power bills. It’s morally wrong, it’s economically unstable.
No no you conservative trogs don’t understand. Left/greens have finally worked out the answer to their lack of popularity when they’ve drained everyone else’s hard-earned. Just print some more.
“Sooner or later the Labour Party run out of other peoples money to spend”.
My hero, Margaret Thatcher.
Hang on Observa. Was it Dumocrats of Repulsivans that stopped printing the M3 data? Let me answer for you. It was under Bush Jr. So he could allow the “Fed. Reserve” to print lots of $ and party like a rock star. Stopping the M3 data hides the fact there are more $’s than cash value. No wonder Hilary psychopath clit-ton cheerfully signed great gobs of the USA as “Eminent Domain” to the Chinese and arabs. Not noticed how things are changing?
But like any dumbocritter you love arabs and….. Let the oils wars begin!
The only green I follow is the green stuff in my back pocket. I make you look like Marx.
Hell, I have no idea what I’m worth. Went long on TSLA from <$45 just before the orders were being fulfilled. So much it nearly gave Dad a heart attack. It reached $192 then shorted it until one caught fire at around $162. The money, 5x more in a few months is in a bank 😛
Might be buying several thousand acres of Southern ex-soviet state now. It's not a debtor nation and bank rates/taxes are very good. Dreaming my next home to be part cave in a hilly region to equalise the yearly climate and full independence with excess. Dunno, better ideas?
Take your point about quasi conservatives masquerading as real conservatives who do understand the lessons of Dicken’s Mr Micawber Andyj. As you know there’s a spectrum of views out there about how long printing IOUs can paper over the cracks appearing in the walls and foundations of willing taxation and fair exchange.
I also have FIT solar on my roof and as a result understand first hand the exact nature of such ‘reshiftables’ and am happy to explain that reality to anyone who wants to listen. When my Gummint put an economic gun to my head with FIT solar I stuck my hands up very quickly and surrendered, as is every citizen’s right to grab whatever pork is going down in the current age of entitlement. However I’m not kidding myself there’s no glaring fallacy of composition in it all and there isn’t a better way of us conducting our economic affairs. Like you, one does what one can to avoid the worst vicissitudes of the current ethos and regime, but I will still argue for a saner way and refuse to give up my BS detector.
Cloth ears!
How many times do I have to tell you, the only carbon tax rebate have been my car and charging point (evse)!
Talk about maintaining a fallacy!
If I was a “survivalist redneck” you could equate to my actions. Instead you keep on inventing who you think I am.
I think you’re naive Andyj IF you think your solar power, with or without FIT, is not costing those without solar power an increase in their power bills because it free-rides on ‘their’ grid. You know that implicitly because like me, you wouldn’t see the economics of investing in enough collectors and battery storage to be completely independent of the grid.
For your information, even if solar could achieve the green theoretical nirvana of 100% efficiency, at next to no cost, it would still be like that car I described with no battery. That’s where hybrid cars are the next best alternative but they’re strictly for wealthy Green poseurs as you know.(perhaps cabbies excepted). Should we all go down that path, soaring battery demand would worsen the already high price of hybrids. Full electric would be even worse in that regard so boutique market they stay.
Observa, WTF are you on about? Just because my (ie) hot water Solar panels saved me the price they cost me after 18 months has nothing to do with anyone else! I am claiming NOTHING!
They save me money. Get over it.
Same with the space heating panels for the house and the Solar electric panels to stymy my large electric demand.
As goes total independence, sure, my house area in this cloudy dank place is not enough and I have no wish to occupy any my garden but the difference to my bills against unit cost/life has been one of my more satisfying investments.
The fact it rewinds my electric meter half the time does not constitute theft. However, with FIT.. Take the US for example. They pay 11.3c/KWH but excess is bought by the company at 3.4c/KWH. Just like the UK.
So who is free riding off who?
Don’t answer. it will only be another daft reply. You keep on paying through the nose. The Gov’t needs sheeple for the carbon tax money.
Oh, by the way. My car consumes 1KWH for every 4.8 miles. In a land of $9 gas don’t you think this non-free ride is a no-brainer either? Not to mention there’s little in the way of engine consumables too. Because doesn’t have an engine.
.
And if you are bothered about Lithium supplies. Don’t worry, just about every other US citizen and his children are eating it for meds. Tons per day. Which ends up down the toilet.
Here ya go DB
http://www.whitehouse.gov/sites/default/files/omb/inforeg/social_cost_of_carbon_for_ria_2013_update.pdf
Technical Support Document: Technical
Update of the Social Cost of Carbon for Regulatory Impact Analysis Under
Executive Order 12866
get that? Executive Order. . .don’t you just LOVE it???
———
we are right on track for a 4 degree C warming by 2070. You and I will be long gone by then so we won’t have to worry about it, but our grandchildren will be living the hellish reality that you, more than most, are directly responsible for creating:
http://rsta.royalsocietypublishing.org/content/369/1934/217.full#T3
a 4°C world would be facing enormous adaptation challenges in the agricultural sector, with large areas of cropland becoming unsuitable for cultivation, and declining agricultural yields. This world would also rapidly be losing its ecosystem services, owing to large losses in biodiversity, forests, coastal wetlands, mangroves and saltmarshes, and terrestrial carbon stores, supported by an acidified and potentially dysfunctional marine ecosystem. Drought and desertification would be widespread, with large numbers of people experiencing increased water stress, and others experiencing changes in seasonality of water supply. There would be a need to shift agricultural cropping to new areas, impinging on unmanaged ecosystems and decreasing their resilience; and large-scale adaptation to sea-level rise would be necessary. Human and natural systems would be subject to increasing levels of agricultural pests and diseases, and increases in the frequency and intensity of extreme weather events.
In such a 4°C world, the limits for human adaptation are likely to be exceeded in many parts of the world, while the limits for adaptation for natural systems would largely be exceeded throughout the world. Hence, the ecosystem services upon which human livelihoods depend would not be preserved. Even though some studies have suggested that adaptation in some areas might still be feasible for human systems, such assessments have generally not taken into account lost ecosystem services.
You cannot have the cake and eat it too..With most people using hot water daily I do believe that solar panels are the best way of utilizing natural energy to its best.
Problem with going solar in the neighborhood where I live is 1/2 the homes have only north facing roofs. No usable south face to the home as it’s all duplexes and town houses. Add in the worst wind comes out of the north, and now we have two reasons not to go solar.
1. roof angle means that only panels nearly straight up would get the best sun
2. The panels now become wind catchers for 70KMH + wind gusts and risk roof damage to the beating it will take.
Greg asked (October 21, 2013 at 10:38 pm):
Solar thermal is about 4x more efficient than PV. Most households use hot water. Why the obsession with PV?
The return on investment for solar water heating is much worse than it is for solar electric power generation. Let’s look at the economics of solar power in my area first.
I have a 9.55 kW solar array on my roof. Generation each year for the past three has ranged from 9,500-9,900 kWh. System cost was about $55K, minus about $16K energy tax credit, for a net of $39K. Our electricity price at the moment is about 10.4 cents/kWh.
Assuming 9,700 kWh of generation in an average year, my system produces about $1,000/year worth of electricity. Assuming a zero percent interest rate, the system would break even in 39 years. In reality, it would die first, so it’s wildly ineconomical (for that reason and for others). The only saving grace is that I have a sweetheart deal (Feed-In Tariff) that will make it pay off in about 10 years. Good for me, bad for everyone else…
Now let’s look at the economics of solar water heating. We heat both the house and our water with natural gas. In July and August, no gas is used for home heating, so those bills are purely for water heating. On average, we pay about $30/month in July and August. Subtract out the $8 customer charge, which we would pay even if we used no gas at all, and the cost of water heating is down to $22/month.
In this area, solar hot water heating would provide all our hot water in the summer and precious little in the winter. According to the folks selling the systems, we would be able to heat about half of our annual hot water with solar. Thus, we would save about half of what we spend for water heating each year: 1/2 * 12 * $22 = $132. A professionally installed solar hot water system is $10,000-$11,000. Assuming we get the “cheap” $10,000 system, solar water heating would pay off in 10,000/132 = 75.75… years. It would take a little less time than that because the price of natural gas will probably go up (with fracking, maybe not), but it’s a good ballpark figure.
Thus, solar water heating would take twice as long to pay back as solar power generation. Further, there isn’t a Feed-In Tariff program available to bring the cost down. So no solar water heating for me. Feel free to take the plunge yourself!
Are you living in the Weimar Republic or something?
My local supplier for vacuum panels and he delivers them for free. “solarproject.co.uk”.
However, I installed a more “industrial strength” pump. £500.
To heat 100 litre tank +20C requires about 3KWH. £0.45 in English money. Include it’s all day “topping up” of heat and my money was saved 18 months from fitting.
Also saved reaching in the airing cupboard to turn it on and the times I forgot to turn it off.
My 4KWH panel array was £3200 plus invertor and sundries. Round up with invertor, could call that £5K..
Electric here is 15p/KWH plus taxes. It’s saving me about £1K/year. In two years I’ll be making a 20% PA return.
Don’t omit the fact the loonies have banned fracking in the UK. Expect old people to die of cold and energy prices to go ever higher and the £ to suffer from energy importation.
Today I could be buying the panels in at half the price. That’s three years and almost 30% return. It’s not my fault if people couldn’t wait to get ripped off 🙁