I hope they find snail darters*;
The US government is putting a hold on new solar energy projects on public land for two years so it can study the environmental impact of sun-driven plants.
The Bureau of Land Management says the moratorium on solar proposals is needed to determine how a new generation of large-scale projects could affect plants and wildlife on the land it manages.
I suggest we stockpile provisions and ammunition, retire to our compounds, and just turn the moonbats loose to run the planet for the next 5 years.
By that time, the earth will be largely cleansed of them, most by starvation, some by suicide. The plowshare-armed stragglers, we can just shoot.
I’d done those calculations some time back,,, and came up with ~900 sq miles for US energy requirements. This, with efficiencies far lower then we can mass produce today
(not to mention that ‘we’ve’ recently discovered that carbon nanotubes can be substituted for two of three layers that the higher efficiency panels are being designed with now (32..45% efficiencies… with all calc. indicating that 50% is achievable)
This area would have to be a sum of areas spread throughout so that we would not be quite so dependent on weather. Yet, quite do-able.
Ric, good post, but there’s something you left out. Cloud cover has a large effect on solar arrays. Three quarters of their production comes from direct sunlight, and only one quarter from indirect. On cloudy days, only indirect sunlight is available. Imagine for a moment that at a given location, cloud cover occurs half the time; you’ve just lost 1/3 of your total electricity production.
Consequently, you might want to increase the total area assessment by between 25 and 50 per cent to allow for lost production and increase storage requirements accordingly.
With respect to area requirements in Ontario, this was assessed by Nathwani, Siddall and Lind, University of Waterloo, in 1994. Their assessment for the province was 4500 square kilometres. Doesn’t sound like much, but it’s about 5 times the total road surface area in the province and about 20 times the total rooftop space. It would constitute about 15 per cent of Ontario’s total agricultural land under cultivation (with obvious and highly adverse environmental effects).
Also, if you’re building it anywhere north of the Mason-Dixon line, you’d best have a hellaciously efficient snow removal system.
Finally, on environmental assessments, the government of Egypt conducted a bio impact study on solar arrays in the Sahara in 1992. The short conclusion of a very long study was that it had unacceptable impacts on the desert biosphere, flora and fauna both.
cgh,
Oh, yes, there are whole hosts of secondary effects that need to be counted in. Among them is the fact that (for some strange reason) the population centers are remote from the best solar-energy sites, requiring long transmission lines and consequent large losses.
Cleaning off dust accumulations is another. My own solar panel goes down as much as 20% in a few days from that factor alone. Snow removal is even worse, but of course when it’s actually snowing the matter is moot.
I was just trying to account for the major factors.
Regards,
Ric
Ric Locke
“Back to the top: 1,140 billion kWh divided by 0.5 kwh/m2 gives 2.24 billion square meters, or 2.24 thousand square kilometers.”
Please recheck your numbers. I get 2280 billion square metres or 2280 thousand square kilometres which is 2.28 MILLION square kilometres.
(Clue: 1,140 divided by half is 2280 not 2.24)
Other than that, you did very well.
Further to h2o’s comment:
The lower 48 US states have a total area of about 8 million sq km. So, using Ric’s numbers, approximately 25% of the entire continental US would be required to supply its energy needs with solar. Let’s take “esin”‘s estimate of eventual 50% conversion efficiency as given; that would reduce the amount of land required to just under 10% of the continental US. I’m sure the enviroweenies would salivate at that proposal.
Meanwhile, how many nuclear power plants would we need to produce 1,140 TWh of energy? In 2006, the Pickering plant outside Toronto produced over 15 TWh from its A & B units. That would need 76 similarly sized plants to meet the US demand (and of course, newer plants generally have higher capacity). The Pickering plant takes up about 2 sq km (about 1/3 of which is employee parking), so if we doubled the size of the plant to 4 sq km, we would be looking at around 300 sq km to produce an equivalent amount of power compared to 2 million sq km needed to do so with solar.
Now, I think it’s important to note that Ric’s figure was for household consumption only. Industrial and business use (motors, A/C, elevators, computers, lights, etc.) is greater than household demand during the day, and so peak generating power is a more important measure than average power produced. I couldn’t find any stats on the “peakiness” of US or Canadian demand, but it’s definitely there, and that’s why we see some stores reducing lighting during very hot days (and while we don’t see it for ourselves, large industrial users often arrange contracts which give them somewhat lower rates with Ontario Hydro but also gives Hydro the right to reduce power to those users significantly during peak demand periods). So we would need even more than the 76 plants to meet the total demand for electricity (and that means more than the 2 million sq km originally posited for a solar alternative).
Finally, as many posters have pointed out already, transmission capacity is an issue that won’t go away. The Ontario government chose the Darlington site for its proposed new nuclear plants over the Bruce Power site on Lake Huron mostly because there is insufficient transmission capacity from Bruce to the GTA where the expected growth in demand will most likely come from. The science of power transmission is very well understood; unlike solar cells, the likelihood of massive improvements in transmission efficiency or capacity is unlikely. Small, dense generators of power located in relative proximity to urban markets are the only possible solution to our future power needs.
One major problem with “run with the river” is there is no storage (hence the name designation). Most of the power is generated during the spring run-off period, which is coincidently, when the load requirement is the lowest. For the rest of the year, typically 8 months and especially during the 5 winter months, generation is negligible. Depending on the river the site may even be shutdown for the winter.
BC Hydro in their future calls will, in all likelihood, place less value on run with the river projects, i.e. pay less per kWH.
Those that promote it are the ones getting paid to. Wind… I’m not even going to go there.
Kevin, the only improvement in transmission at this time is using DC rather than AC to reduce line losses, with the added burden of needing AC/DC converters every time we need to transform. We’re stuck with aluminum cable for the foreseeable future. As far as peak demand goes, I’m only intimately familiar with the Ontario system. Typical daily summer peak demand is 25,000 MW with overnight baseload requirement of about 18,000 MW.
Ric, one other thing you might want to think about. I understand that solar panels are subject to very high losses from reflection and refraction effects from even very light surface scratching. It suggests that the lifespan of an outdoor installation may not be that long. I believe this was a problem for some of the prototype projects in the US southwest in the early 1980s.
cgh,
That’s true of the bare panels. Any realistic installation would have glazing, as my small panel does now. That gives a percent or two of loss, included in the “average 15% efficiency” number.
Oh, and H2O is absolutely correct. I dropped three orders of magnitude in the calculations!
Regards,
Ric