Opinion: Why Buffett Bet A Billion On Solar: Miles Per Acre Per Year
29 June 2015
by Henry Hewitt for Oilprice.com
During the late innings of the ICE-age (as in the Internal Combustion Engine age) it has become clear that feeding gasoline and diesel to the next billion new cars is not going to be easy, or cheap. In China alone, 500 million new vehicles can be expected to jam the roads between now and 2030.
That may sound far-fetched, but considering annual sales have already made it to 25 million units per year (vs. around 17 million in the US—China became the top market in 2009), it only requires a 4 percent growth rate to reach that target in fifteen years.
The cost to operate an EV, per mile, is already well below the cost to drive a standard ICE-age model, and the advantage is likely to widen. The average US residential customer pays 12 cents per kilowatt-hour (kWh), which means the cost to drive one mile in an EV is somewhat less than 4 cents. By contrast, at 25 miles per $3 gallon of gasoline, those miles cost 12 cents each.
Coal still supplies more power in the US than anything else, with natural gas next. However, building more coal and gas power plants to make miles for transport is counter-productive if the game plan is to reduce carbon output.
Fortunately, abundant renewable power is getting cheaper, while gasoline from finite fossil fuels may get more expensive. (Even after the fall in US crude, gasoline in California costs $4 on average. At that price, California miles are 16 cents each. If you drive an SUV in Southern California those miles cost over 30 cents each.)
Even though not all renewables are created equal, power purchase agreements (PPAs) for PV projects with utilities in the US Southwest are now coming in under seven cents per kWh for a twenty year period. At that rate, the cost to operate an electric vehicle is 2 cents per mile. Hydropower in Seattle will push you around for the same price. The first eye-opener for large scale solar was the Austin Energy PPA last year that was priced at 5 cents. What this country needed was a good 5-cent kWh, and now we have it.
It is generous to say that an acre of Iowa can provide 12,500 miles per year at a cost of 10 cents each. (Average fuel efficiency in the US is 22 miles per gallon (mpg). New cars in 2015 get 25 mpg.) An acre of corn that provides 500 gallons of ethanol, at 22 mpg, gives you 11,000 miles, or would, if such gallons had the same energy content as a gallon of gasoline.
Unfortunately, they don’t. Ethanol packs about 70 percent of the punch of gasoline, so you actually need 1.4 gallons of ethanol to get you as far as a gallon of gas. (Instead of 11,000 miles per acre for the average 22 mpg model, the figure drops to 7,850 miles per acre per year.)
But suppose your new car is up to current Chinese standards (~35 mpg). In that case, Iowa’s acres provide 12,500 miles in a year (17,500/1.4). This is still roughly two orders of magnitude less output per acre than Warren Buffett’s Agua Caliente array in Arizona. No wonder Berkshire Hathaway has already bet a billion on PV arrays. One could say that Mr. Buffett has not only seen the light but invested heavily therein.
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| Agua Caliente PV Plant: Yuma Arizona. Click to enlarge. |
Sunrise in the Desert. An acre of desert in Arizona, Nevada and many other places on earth sees on the order of 3,000 hours of direct sun per year. (This amounts to 34 percent of the total 8,765 hours available, half being dark.) PV arrays on a house are spaced closely together and it is reasonable to figure 250 kilowatts (kW) per acre of aggregated rooftops. However, it costs more to build an acre of rooftop PV. On the ground the figure is closer to 150 kW per acre.
The biggest difference between rooftop and most of the utility scale arrays yet to be built is that it makes sense, when possible, to track the sun. Since not everyone can afford to build houses that track the sun, let•s just assume that all residential rooftop arrays will be fixed. In the commercial sector, and in the case of community solar, there is more flexibility and tracking arrays may make sense, especially when mounted on the ground.
The arithmetic is pretty simple. You get about 20 percent more yield by tracking the sun. A rooftop array is pointed directly at the sun (known as direct normal irradiance) only for a short while each day, assuming the roof pitch is right, and most aren’t. If it costs 10 percent more to get that 20 percent extra yield, do it.
Critics will say that more structure and added tracking motors and mechanisms will add to the chance of system failure. This, however, is a fallacy. Consider the venerable oil drilling donkey, which cycles once every 7 or 8 seconds. At this rate (480 cycles per hour, and 11,520 cycles per day), these ancient and effective oil rigs cycle more in a day than a tracking PV array in its 30-year lifetime. (365.25 days x 30 years = 10,957 cycles.)
An acre of desert PV will easily yield 300,000 kWh (150 kW per acre x 2,000 hours of direct normal sun) and a million miles per year for an EV. Since 2,500 to 3,000 hours are available in many places, the figure jumps to between 375,000 and 450,000 kWh per year, yielding between 1.25 million and 1.5 million miles per acre per year.
In other words, the output from (more expensive) ethanol is little more than a rounding error compared to the output from PV. The choice is between a million miles per acre per year, costing 2 to 4 cents each from the sun, or 10,000 miles per year costing 12 to 20 cents from a cornfield that would be better served making food.
Even if the figures were more supportive of the ethanol case, biomass in general does not scale very well. Silicon based PV, on the other hand, is hugely scalable and relatively cheap. It really isn’t a fair fight.
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| Click to enlarge. |
The calculation for rooftop solar is not quite as straightforward as multiplying the number of kilowatts by the number of hours of sun in a year. NREL has done the math on how many kWh you get from a fixed (non-tracking) array per day from a square meter depending upon location. It is roughly the measure of how many hours per day the panels will produce peak power. The US average is around four hours which means that,
For an individual homeowner, a 3-kW PV system in a less than arid region will still yield 4,000 kWh (3 kW x 4 hours x 365 days) and enough EV miles to cover the average annual 12,000-15,000 miles of commuting. Even at 15 cents per solar kWh (and, as mentioned, many PPAs are coming in at half that figure or less), you will save about 10 cents per mile over the gasoline price. The 5-year fuel savings will pay for a 3-kW system.
Chevron, ExxonMobil and Shell cannot stop this; they will begin to bleed trillions of miles per year. They had better think seriously about financing solar and wind arrays. The estimated one million EVs on world roads by the end of this year will cover roughly 10 billion miles per year, and over 100 million miles over their lifetime. What will ExxonMobil’s share price be when cumulative EV sales reach 100 million units?
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| Cumulative EV Sales Worldwide. Click to enlarge. |
By 2030, millions of people will have transport fuel that is “on the house.” During the midday hours, many grids will experience negative pricing as solar PV floods the market to the extent that the power cannot be stored. As millions of EVs hit the road, four percent of the time, on average (the rest of the time they are in a garage or parked on the street), they will likely become the default destination for stored electricity.
When there are 100 million EVs, figuring 60 kWh batteries, the fleet will provide 6 terawatt-hours of storage, enough to run the US (with 1,000 GW, or 1 Terawatt, of power capacity) at peak power for six hours, or the world (with 5 Terawatts of capacity ) for over an hour. If all the cars sold in the US this year were electric, their battery capacity would be sufficient to power the country for an hour (17 million vehicles x 60 kWh). How many gigafactories will Mr. Musk have to build?
Henry Hewitt is an investment strategist and portfolio manager with 36 years of experience in renewable energy.
Source: http://oilprice.com/Energy/Energy-General/Why-Buffett-Bet-A-Billion-On-Solar.html
Good to read such positive stuff from an Oil-industry Journal. Thanks Mike.
Posted by: Peterww | 29 June 2015 at 03:27 AM
Since not everyone lives in the South West getting the electricity to them is non-trivial.
Winter also has a considerable effect, and if you are going to do enough of an overbuild to at least partially cover that it makes sense to turn the surplus into hydrogen.
Posted by: Davemart | 29 June 2015 at 03:48 AM
America averages TWICE the solar radiance of Germany, yet Germany profits from solar.
Many of the expensive early 2000's German solar(and wind) installations have paid for themselves - meaning nearly free energy for future generations.
Not only will STEM-weak(or lazy or misled) Americans try to compete with those cheaper energy costs, but also a technical society of world-class scientists, engineers, and technicians with a generation of renewable energy experience in their very homes.
Fortunately, America has a dozen years of the Bush Hydrogen Initiative with its deep fuel cell vehicle infrastructure.
Posted by: kelly | 29 June 2015 at 06:28 AM
All the expert analysis that I've read have solar power increasing, but starting from zero, high growth rates easy. The actual portion of contribution to grid is projected to be marginal for foreseeable future. Coal will maintain dominance within international community. U.S. has abundant reserves of cheap NG and the fuel is expected to continue to increase power production, but coal maintains a heavy contributor. Your corn ethanol figures a bit off. If were comparing to ideal solar we need to compare ethanol likewise. For example mpg of ethanol not a mere factor of btu rating. Quality of fuel character has big impact on ICE ability to achieve high efficiency. The simple and pure molecule of ethanol can oxidize with less energy waste. Octane and liquid chemical oxygen content contribute to efficient burn, as well. Efficient ethanol ICE engines are beating diesel, i.e. Cummins medium duty van engine. The mileage surpasses gasoline vehicle option and cost per mile is equal to diesel option, but the E85 engine is lighter, cheaper, and produces better torque and horsepower curves for improved driver experience.
Farm bushel per acre production is expected to continue to trend up, with the goal being 300 bushel per acre. Modern ethanol plants now acheive 3.1 gallon/bushel. Don't forget the high quality DDGs, corn oil, and host of other valuable coproducts including methane. Cellulosic ethanol is expected to push those gallon per acre up another 30-50%. Process efficiency of cellulosic conversion on path from 67% to 98% as advertised by a supply company. Farmers are expected to plant perennial feed stock that achieve 1,000 gallons/acre on poor soils less suitable to grain. Waste ethanol is steadily increasing supply and solving disposal problems. Algae and fungi solutions continue to look attractive with adaptations to typical ethanol plant. Cellulosic process also looks to be adaptable to such plant process. Infrastructure cost and delay minimal with increase use of ethanol. No change in consumer behavior required. Ethanol is not the single solution and neither is BEV or solar.
Posted by: Trees | 29 June 2015 at 06:55 AM
I'd feel better about farmed ethanol if the farm equipment wasn't run on fossil fuels.
https://www.organicconsumers.org/old_articles/corp/fossil-fuels.php
Between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%. That is a tremendous increase in the amount of food energy available for human consumption. This additional energy did not come from an increase in incipient sunlight, nor did it result from introducing agriculture to new vistas of land. The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), and hydrocarbon fueled irrigation.
The Green Revolution increased the energy flow to agriculture by an average of 50 times the energy input of traditional agriculture. In the most extreme cases, energy consumption by agriculture has increased 100 fold or more.
In the United States, 400 gallons of oil equivalents are expended annually to feed each American (as of data provided in 1994). Agricultural energy consumption is broken down as follows:
31% for the manufacture of inorganic fertilizer
19% for the operation of field machinery
16% for transportation
13% for irrigation
08% for raising livestock (not including livestock feed)
05% for crop drying
05% for pesticide production
08% miscellaneous
http://www.sustainabletable.org/982/agriculture-energy-climate-change
Posted by: ai_vin | 29 June 2015 at 08:01 AM
BTW another source I found claimed it was even worst: "Between 1910 and 1983, corn yields in the US increased by 346% (on a per area basis), which the energy inputs increased by 810%, also on a per area basis."
Posted by: ai_vin | 29 June 2015 at 08:04 AM
In the not too distant future, corn ethanol production will be restricted to suppy niche markets such as for airplanes. It is a non-sustainable way to produce basic energy.
With near and mid terms electrification of most transportation means, Solar, Wind and improved cleaner Nuclear energy production will increase drastically.
Solar is probably one of the cleanest way to do it. Lower cost storage will come about soon together with lower cost H2 production for FCEVs.
Posted by: HarveyD | 29 June 2015 at 08:21 AM
@kelly:
The last estimates I saw put the cost of switching to renewables for Germany at well over a trillion dollars.
Germany uses a lot more solar than the US with half the resources, profiting from it is a different matter.
Posted by: Davemart | 29 June 2015 at 08:45 AM
There are many more important reasons to justify a fleet conversion to EVs than basic fuel/energy consumption. Households with a rooftop solar array (matched to large battery BEVs and small battery PHEVs) gain a backup power supply vital in an emergency grid failure, a choice to use electricity for household uses or for driving, a means to more closely monitor and reduce both household energy consumption and driving.
Warren Buffett will invest in vast solar facilities in the desert only to control the power supply and discourage rooftop solar. Nevermind that the most resilient regional utility grid is achieved with rooftop solar, the advancement in public safety takes back seat to Mr Buffett remaining a mad energy mogul.
Posted by: Sirkulat | 29 June 2015 at 09:34 AM
If there will be sufficient number of 20-mi-PHEV's, then there will exist a market for solar carport charging at work. You'll pay to park underneath that charging solar carport via a monthly subscription fee, which will rent you a cool and shaded place to park that will be closer to the building, or with a covered walkway always from the parking lot to the building. The covered walkway will also be covered with solar PV panels. No need for expensive power meter at every solar parking slot because of a fixed monthly parking fee, so no extra accounting or billing costs.
With DC charging, you'll gain higher efficiency at lower cost. No need for expensive grid-compatible DC to AC inverters. Weekend solar output will be used to make H2 for FCEV's or for FC-PHEV's, so still DC to DC consumption. So, people who have FCEV's or FC-PHEV's will fill up their H2 tanks at their workplaces, right after the end of each Fridays for their weekend travels, allowing room for more weekend H2 production.
Cloudy days are usually windy, in that case, there will be excess wind power for charging or for making H2. Having an ability to soak up the extra solar and wind energy will encourage more rapid adoption of RE by being able to obtain high-value transportation fuel out of the EXCESS RE that otherwise would go to waste, with very high penetration of RE into our future power grid.
If you work for Mr. Musk, please persuade him to expand his Solar City business into solar carports for at work charging. He can also work out a deal with ITM-Power to provide H2 fillup facilities in the work place, as well as working with Intelligent Energy to provide FC for the Model S and X, while working with Quantum Fuel System to obtain H2 tanks for those future Model S and X in FC-PHEV format. Those FC-PHEV's can be plugged-in daily at work for low-cost and high-efficiency solar charging, as well as using rapid-fill H2 made from EXCESS RE for long-distance travels on the weekends and holidays.
If you work for the petroleum industry, you may also wanna persuade your employer to diversify into RE, batteries and hydrogen. Shell Oil is now building H2-filling stations in Europe. Exxon-Mobil, Valero, Texaco, etc can do the same to build H2-filling stations here in the USA. Then, you will not have to worry about NO INFRASTRUCTURE for H2 ever again.
No more worrying about using public money to build H2 stations ever again, when the deep-pocketed energy companies will build those H2 infrastructure.
Notice how PEV's (Plugged-in EV) and FCEV's can complement each others nicely and completely in the exploitation of Renewable Energy. With more RE developments thanks to cooperation between PEV's and FCEV's, we will be much faster on our way with energy security, environmental cleanup, and averting the GW crisis!
Posted by: Roger Pham | 29 June 2015 at 09:40 AM
Ethanol energy ratios well studied. Each processing path is different, but on average, 2.3 to 1 for average good dry mill operation and farming. More efficient processing plants 2.8:1. This is total of all energy inputs (including fertilizer) vs energy out aka ethanol. Now, this ratio is improving for ethanol as they are attempting better carbon rating. The average processing plant hasn't yet utilized the anaerobic digestor process improvement. This will displace some natural gas. Coproducing with cellulosic has proven to a big energy improvement. Some plants are utilizing CHP waste energy from power plants. New technology claims a 75% decrease in distillation energy. Algae may be utilize within the CO2 waste stream for extra ethanol, biomass is sometime utilized either farm or forest. One fact remains, crude oil is getting more expensive to harvest and ethanol process is becoming more efficient. Include the transportation costs of crude oil from well to refinery then back out to consumer, not good. Crude oil and finished products suffer many an international trip. The efficiency of the pipeline improves oil energy balance, but new pipeline construction easily upgraded for ethanol as well. Ethanol produced locally. My SW Michigan ethanol suffers 60 mile trip from farm to gas pump. Know that petrol proponents often leave out crediting ethanol with the coproduct production, utilize outdated data, leave the reader with impression that all corn is irrigated (9 out 10 acres use natural rain water), account sunshine as an energy input, etc. Also, up to date data on fertilizer use is dropping upon farms growing use of satellite and computer controlled steering, and fertilizer applications. Studies of the farm cellulosic feedstock look to be 26:1 energy return. The cogeneration with corn ethanol will boost corn ethanol ratio as well. And yes the E85 high torque engine such as Cummins appears to be a step above diesel for torque, lower cost, and clean air. If ethanol production continues to increase, the E85 engine would migrate to farm tractors.
Posted by: Trees | 29 June 2015 at 09:52 AM
Ideally, every residential home could be built to produce all the Solar energy needed to keep the residents within the comfort level.
No new technologies are required and it has already been done in many places.
The extra 10% to 12% in construction cost could be covered with interest free loans or subsidies, to lower GHGs and create new jobs.
Posted by: HarveyD | 29 June 2015 at 11:00 AM
Notes on the article -
Solar PPAs have been clustered around 5 cents per kWh for the last couple of years with reports of 4 cent per kWh PPAs now being signed.
http://emp.lbl.gov/sites/all/files/LBNL_Utility-Scale_Solar_2013_report.pdf
There's a good chance that EVs will charge as dispatchable load which would mean even lower than average (12 cent) prices. Likely a very sweet price when sucking down surplus supply.
"building more coal and gas power plants to make miles for transport is counter-productive if the game plan is to reduce carbon output"
New wind and solar are very much cheaper than new coal on a kWh basis. Wind is cheaper than new NG and solar will soon be.
"It is generous to say that an acre of Iowa"
Those Iowa acres. Iowa is really windy. A 3 MW wind turbine takes one quarter acre of land. One could install 12 MW to the acre (as long as the quarter acres are not adjacent. Capacity factors are now reaching 50%. 12 MW at 45% CF would mean 47,300 MWh of electricity a year per acre. About 158 million EV miles to the acre.
"it makes sense, when possible, to track the sun"
As the cost of panels drops it makes less sense to track the Sun. It makes more sense to install more panels, orient some east and some west in order to extend the solar day. Point the majority south and charge EVs right in the middle of the day. (Along with late night hours - see wind above.)
"During the midday hours, many grids will experience negative pricing as solar PV floods the market to the extent that the power cannot be stored."
Only until coal and nuclear plants are closed. No one is going to pay the grid to take their solar (or wind) power. If they can't make anything they will simply curtail. Coal and nuclear sell at a significant loss because they do not want to shut down and then spend time restarting.
"How many gigafactories will Mr. Musk have to build?"
The question is how many gigafactories of capacity will all the world's battery manufacturers build over the next 20-30 years? Tesla was first off the line when the gun sounded. Other manufacturers such as LG Chem and BYD have made their moves.
Posted by: Bob Wallace | 29 June 2015 at 11:12 AM
Davemart - states that lack excellent solar resources are generally rich (enough) in something else. You can see what a 100% renewable energy mix for each state might look like here -
http://thesolutionsproject.org/infographic/
Emily - NG is not a long term solution. NG is finite. So is solar, but we've got a 4 -5 billion year supply.
Here's the bottom line. Wind and solar are now dropping below 5 cents per kWh - unsubsidized. Onshore wind in the US is just under 4 cents and dropping. Solar is a penny or so above 5 cents but dropping fast.
This is a moving target that cannot be hit with petroleum, hydrogen or biofuel.
The cost of batteries is rapidly dropping. Capacity is increasing.
EVs are becoming a force.
Posted by: Bob Wallace | 29 June 2015 at 11:23 AM
I agree that solar energy is a good bet.
I do not agree it means the end of ICE.
This analysis ignores at least two factors:
1. The cost-per mile ignores battery replacement cost. Li-ion battery production consumes vast amounts of energy. In a fossil fuel free world, that energy can't come from coal.
2. Once you bring solar energy into the equation, land area is no longer a constraint. Suppose, for example, that crude oil demand eventually stabilises at 18 billion tonnes per year, 4.5 times greater than current production. This would need solar energy collectors covering less than 0.63% of the earth's land area. If the land coverage factor is 30%, crude oil production needs only about 2% of world land area. With solar thermal, waster heat from crude oil plants could desalinate vast quantities of water. And the land between solar collectors could be used for horticulture.
So, if land area is not a constraint, and if a BEV's lifetime energy consumption is comparable with that of a 21st century ICE, why favour batteries over internal combustion.
The world needs different horses for courses. This is probably why car manufacturers are pushing all technologies - ICE, BEV, and HFC.
As long as they have wheels they're all good as far as I'm concerned
Posted by: Kevin Cudby | 29 June 2015 at 11:28 AM
Although the batteries used in EVs usually only have a vehicle lifetime of 8-10 years, they still have significant capacity left (~80%) for alternative uses. Finding secondary uses for the EV batteries reduces their up-front cost and provides benefits to consumers and utilities, such as demand charge management, renewable energy integration and regulation energy management.
https://www.law.berkeley.edu/files/ccelp/Reuse_and_Repower_--_Web_Copy.pdf
http://www.nrel.gov/transportation/energystorage/pdfs/48018.pdf
Ironically, the larger battery packs that were put into cars like the Tesla model S to allay the range anxiety of EV drivers will likely end up staying in their cars for the car's lifetime as the owners will overcome their fears and learn they don't actually need that much range.
Posted by: ai_vin | 29 June 2015 at 12:19 PM
Kevin, glad to hear that you're onboard with solar but your argument about ICEs completely ignores the reason they will be phased out: pollution. No just SOx and NOx and particulates, benzene etc, but now CO2. Life gets very uncomfortable after the crops fail and massive species extinction. That's not some far flung hypothetical, that is now my friend. We are having our Wile E. Coyote moment now.
Battery replacement argument is a canard. 24kWh batteries do not get tossed on the slag heap after 150,000 miles. They get used for stationary storage for another 25 years or more. And then recycled.
The "vast amount of energy to produce" is hyperbole. Do you really believe a battery is a whole lot more energy intensive to produce to than an ICE engine with cast iron, aluminum, forged and CNC milled parts? Thousands of parts. Each requiring mining, refining, production, assembly, shipping etc. Please cite any credible source that shows how much more "vast" the energy required to produce a battery is.
Posted by: electric-car-insider.com | 29 June 2015 at 12:45 PM
The basic point of this article is that you get 100x as many miles / acre from PV+EV (or "big" wind) as from ICE+Ethanol.
This should be pretty compelling but it may take a while to come through.
It may happen first in countries where people are not accustomed to the unlimited range of ICEs (namely China and India).
These people are accustomed to using a train or bus for longer journeys now and they could get used to the same or renting (or temp-swapping).
If you accept that Leaf range is enough for "most" people, "most of the time", you have the solution right there, now.
All you need is workplace charging stations by the million (so cars can be charged from daytime PV) and these only have to be about 3Kw so they do not need to be expensive. Solar porches are nice, but you don't need them, you already have the grid.
You will want to keep the fossil fuel for aircraft and long range trucks and the odd ICE (and ICEs in "crazy" places like the USA where they still insist on owning and driving 300 mile vehicles).
PHEvs are a nice solution, but they are a bit "technology heavy" requiring two full sized engines.
(Maybe a 25Kw range extender would to the trick).
Also, the people in China may find that there is not enough room for 500M EVs on the roads and revert to public travel which has a much greater "human per square metre" metric than individually driven cars.
Posted by: mahonj | 29 June 2015 at 12:50 PM
EOI, Energy Stored On Invested is 10:1 for lithium ion batteries according to Stanford Univ study. 16 year life if full cycled every day of the year.
http://news.stanford.edu/news/2013/march/store-electric-grid-030513.html
http://pubs.rsc.org/en/content/articlelanding/2013/ee/c3ee24040a#!divAbstract
Posted by: electric-car-insider.com | 29 June 2015 at 12:59 PM
Anyone w/ a couple square meters of open, south-facing area can:
- buy a 250 watt solar panel for under $250
- buy a 250 watt grid-tie inverter for under $100 (ex: http://www.amazon.com/Power-Inverter-Converter-Solar-10-8v-30v/dp/B004TVEF8Y )
- buy a Kill-A-Watt meter and wire/solar cord for under $50
angle the panel at ~45 degrees with 2 by 4s, connect the +/- panel terminals to the grid inverter, plug the grid inverter into the Kill-A-Watt meter and the meter into a 120 VAC wall plug.
One will save over a 1,000 watt hour(1 kwh) per clear day, accumulated on the Kill-A-Watt meter reading.
The electric bill will be smaller and as the years pass one notices how reliable 'no moving parts' solar power really is.
The fun part is when electricity home use is low, one can watch the analog utility meter TURN BACKWARDS.
Posted by: kelly | 29 June 2015 at 02:25 PM
Anyone w/ a couple square meters of open, south-facing area can:
- buy a 250 watt solar panel for under $250
- buy a 250 watt grid-tie inverter for under $100 (ex: http://www.amazon.com/Power-Inverter-Converter-Solar-10-8v-30v/dp/B004TVEF8Y )
- buy a Kill-A-Watt meter and wire/solar cord for under $50
angle the panel at ~45 degrees with 2 by 4s, connect the +/- panel terminals to the grid inverter, plug the grid inverter into the Kill-A-Watt meter and the meter into a 120 VAC wall plug.
One will save over a 1,000 watt hour(1 kwh) per clear day, accumulated on the Kill-A-Watt meter reading.
The electric bill will be smaller and as the years pass one notices how reliable 'no moving parts' solar power really is.
The fun part is when electricity home use is low, one can watch the analog utility meter TURN BACKWARDS.
Posted by: kelly | 29 June 2015 at 02:27 PM
It's funny to watch the big-ag boosters like Emily and the windbags like Bob Wallace fight over who's better, while ignoring the elephant in the room:
Nuclear power.
A two-unit AP1000 installation, nameplate power ~2200 MW, occupies roughly 1 square mile (640 acres). Figuring 0.9 capacity factor and 3 miles per kWh, this plant would average about 5.9 million miles range per hour, 52 billion miles per year, 81 million miles per acre per year. That's counting the greenbelt around the plant in the total area.
Bob's figure of 1/4 acre per unit is only the base pad, not the actual area excluded from other turbines or the area unusable for most purposes beneath power line rights-of-way. The vast areas required to collect diffuse flows such as wind requires lots and lots of power lines and the cleared zones beneath them. Every mile of a 150-foot ROW is 18 acres (72 pad's worth), and there are a lot of miles between the windy plains and population centers.
But the real kicker is reliability. If you get a cloudy or calm day, you're not charging your EV and falling back to fossil fuels; nuclear doesn't care what the weather is doing as long as the lines stay up.
Nuclear is the real fossil-killer. Everyone else is just shilling for the natural gas industry whether they know it or not.
Posted by: Engineer-Poet | 29 June 2015 at 05:50 PM
@Engineer-Poet
A two-unit AP1000 installation is going to run more than 13 cents per kilowatt-hour for a 25 year PPA - that's with subisidized disaster insurance, mind you, and a totally unknown result for the spent fuel.
And land is cheap.
640 acres in Worcester County, MA? 6 million dollars, vs. the $12 billion dollar cost of the pair of nuclear reactors. 1/2000th of the plant cost.
http://www.landwatch.com/Massachusetts_land_for_sale/Worcester_County
With First Solar confidently predicting prices in 2017 that equate to 3.5 cents per kilowatt-hour in Texas (unsubsidized) nuclear is dead in the USA.
http://www.greentechmedia.com/articles/read/First-Solar-CEO-By-2017-Well-be-Under-1.00-Per-Watt-Fully-Installed
A solar pv plant of one watt, plus batteries to store 40% of the energy generated, plus buying natural gas combined cycle turbines of one watt (which is likely not even necessary as it already exists), and planting trees to offset any and all fossil use is vastly cheaper than new nuclear. Even if you run the turbines on biomethane its vastly cheaper.
Your lame youtube link references solar thermal which everyone realized was getting roundly beaten by solar pv about 2011.
If nuclear is the elephant in the room it is the dead radioactive one whose carcass fascinatingly will not rot due to the radiation that kills any bacteria. For centuries.
Posted by: NewtonPulsifer | 29 June 2015 at 08:59 PM
It is nice to see that more people realize that solar power and wind power is affordable already and is going to become the lowest cost energy we can make in a few decades. I would say the average cost of new utility scale solar power is about 10 cents kwh now and we are heading for 3 cents per kwh in 2035. Wind power is about 6 cents per kwh and going down to about 3 cents per kwh by 2035.
In 2014 50 GW of wind power and 40GW of solar power was added to the global grid for about 250 billion USD. It has become big business now but solar and wind needs to grow 11 fold to about 1000 GW per year in new capacity added. At that rate it will take 25 years to get 25,000 GW of solar and wind power globally and that is enough to power the entire planet without any biofuels or fossil fuels or nuclear or anything else. It can be done and it should be done for so many good reasons like eliminating air pollution, making cancer a rare disease, eliminating oil dependence, creating local jobs, stopping the ongoing Holocene mass-extinction event see https://en.wikipedia.org/wiki/Holocene_extinction
EP as you know solar power is nuclear power. It all comes from the giant fusion reactor at the center of our solar system, the sun. And the sun can be trusted not to blow up for at least one billion years to come. It is as reliable as it gets.
Posted by: Account Deleted | 30 June 2015 at 12:57 AM
So you'll be generating vast amounts of 3.5¢/kWh juice in the late spring/early summer days when you don't need it, and have nothing on the winter nights when you need it desperately.
You think only 40% needs to be stored? The people who actually live on RE systems say you need DAYS worth of storage, as in a minimum of 3 days. Figure more like 60% going through storage. 1 W(avg) of solar (about 5 W(peak)) with 0.6 W going into storage requires maybe 36 Wh of storage to hold 3 days of consumption. At $0.10/Wh future price of Li-ion, that's $3.60 of battery per average watt. Financed at 7% and replaced every 10 years, the battery alone costs 5.7¢/kWh. Then you have the financing and O&M of the backups, because there WILL be deficits too long and deep to be served from your storage.
You can't use natural gas plants in a carbon-constrained world, and there isn't enough net biological productivity to feed them with biomethane.
The reality is that trees are disappearing, being burned and blown into the atmosphere. Germany is strip-mining its forests for "renewable" generating fuel, and Georgia forests are being clearcut and shipped to Europe as wood pellets. Essentially, you advocate denuding the forests to save them. This isn't even cutting atmospheric CO2, because burning wood emits more CO2 per kWh and cutting the trees slashes the carbon capture of that area for many years.
Meanwhile, people have been living in the "deadly" Chernobyl exclusion zone for many years with no ill effects. Even the infamously paranoid Japanese are going back to the region of Fukushima. People vacation on the beach at Guarapari where they receive upwards of 50 μSv/hour from the thorium and its decay daughters... and they go there for their health.
You should be ashamed of what you just wrote. It is an irresponsible piece of fear-mongering, and you should retract it.
Posted by: Engineer-Poet | 30 June 2015 at 09:30 AM