Wind, solar could provide 99.9% of ALL POWER by 2030
Even better: It could do so at the same cost as fossil fuels
A group of researchers has released a study that claims to shoot down the common perception that clean, renewable energy from wind and solar sources is all well and good, eco-wise, but that it's too uncertain, sporadic, and pricey for widespread use.
"These results break the conventional wisdom that renewable energy is too unreliable and expensive," said professor Willett Kempton of the University of Delaware in a statement. "The key is to get the right combination of electricity sources and storage – which we did by an exhaustive search – and to calculate costs correctly.”
This good news is detailed in a paper available online now and scheduled to be published in the March 2013 issue of the scholarly Journal of Power Sources, straightforwardly entitled "Cost-minimized combinations of wind power, solar power and electrochemical storage, powering the grid up to 99.9% of the time".
When Kempton referred to an exhaustive effort, he wasn't merely whistling the proverbial Dixie. The six authors of the paper used computer modeling to study 28 billion – that's with a "B" – combinations of energy sources and storage techniques. Each of those 28 beeeelion combos were tested against four years of actual hourly weather data, along with electricity-demand data from PJM Interconnection, a power grid that serve 13 states from New Jersey to South Carolina to Illinois – about one-fifth of the US grid.
Big enough sample for ya?
As a result of this intensive modeling effort, the researchers say they've discovered that a carefully designed combination of renewable sources – wind and solar – with batteries and fuel-cell electricity-storage systems could by 2030 supply enough power to keep a large electrical grid fired up 99.9 per cent of the time, and do so at a cost comparable to today's not-so-renewable energy grid.
Four years of historical data applied to a mega-sized renewables, storage, and fossil-fuel grid model
Cost was central to the team's work. With this in mind, one of the things that they discovered is that it's cheaper to crank out more juice than needed during hours of average need – as much as three times as much – than it is to store all the extra energy for later use. Those batteries and fuel cells ain't cheap.
One of the key elements in their plan would be to have a widespread geographical distribution of such intermittent sources as wind farms and photovoltaic installations – when it's windy and sunny in one location on the grid, it could be calm and overcast in another and all parts of the grid would have enough power.
Another aspect of their plan is to use some of that extra renewable capacity, when it's available and when storage capacity is full, to substitute for natural gas for home and business heating.
Fossil-fuel sources wouldn't be abandoned entirely. There would likely be times when neither wind nor solar could provide enough juice, and when storage had been depleted. When that happens, they say, it'd be time to fire up the ol' CO2 spewers and spin their turbines. Doing that, however, would be a last resort, and not the first, as is true in much of the US's power grid today.
While the idea of a large, geographically diverse renewable-energy grid might seem heinously expensive, the paper's authors contend that if current estimates are correct that by 2030 wind and solar capital costs will be about half of what they are today, by that date a renewable system would be as cost effective as a fossil fuel system, and all without government subsidies.
There is one cost sweetener in their calculations, however: their cost estimates for that comparison includes the costs related to the human health effects of fossil fuel–caused air polution.
Those are costs, of course, that are not borne by the electric power industry. Yet. ®
Re: Let's do it.
Industry AC back again, replying from a UK perspective.
I doubt that this really stacks up. There's caveats in here about carbon taxes and other eco-optimism that simply don't seem credible. UK electricity industry was asked by DECC to look at how much wind power actually contributed on the 100 coldest days of the year in aggregate. The answer, to DECC's horror was 6% of rated capacity. So although wind works, it doesn't work when you might really want it, which also tends to be night time, or in winter when the low azimuth of the sun reduces the capacity of solar even when the sun does shine. Geographic distribution helps a little, but the problem with low wind is that it is routinely associated with relatively stable high pressure systems, these can be large enough to cover most of Europe and persist for many days (hence the 100 day study above).
The US study accepts fossil back up, but given that you need to cover combinations of peak winter demand with virtually no wind or solar, and the claim is that they can normally run the system entirely off renewables what you need is the following recipe:
- 100% of peak demand covered by fossil or nuke plant (or cutting off industrial users)
- A combination of wind and solar that can actually deliver around 150% of peak demand (so enabling this to cover normal demand, and feed into storage at the same time). Note that because wind is always intermittent, the load factor is at absolute best 35%, so to cover half of the 150% with wind means you'd need to build 3x75%, or more than double the peak network demand capacity.
- Storage capacity of around (and I'm guessing this) 40-60% of peak summer demand.
If you look at that on a very rounded basis that approximates to paying for your electricity capacity four to five times over. So, yes, it could be done. But it will not be "at the same cost as fossil plant", but rather at the "same cost as fossil plant after we've rigged the system to pay for the EPA's eco-toys of which we'll need huge amounts more".
Two minor points of further detail:
One, a power plant built today (even a cheap and cheerful CCGT) could still expect to be working in 2040 or even 2050. Power plant CCGT are much bigger and slower spinning than aircraft engines, and built for long life and durability.
Two. You comment that a privatised electricity business won't plan this well. In the UK network performance has been far better since privatisation, and there is a single central system operator, National Grid plc. It isn't a set of random power stations being built and generating when they feel like it. In terms of the mess of energy policy, that is the fault of government. But unfortunately government are taking more and more control (despite their proven incompetence in all such things), so expect the situation to get worse, not better.
Ummm... this is a MODELED finding?
" Each of those 28 beeeelion combos were tested against four years of actual hourly weather data, along with electricity-demand data .... Big enough sample for ya?"
And they found how many were able to handle the job? One? That could equally generate the following heading:
'Billion to one chance of renewables powering a country'... which is about right....
Separately, I notice that the whole process was a model, with assumptions like 'renewables will drop greatly in price'. Let me run a billion variations of a model while allowing me to input assumptions, and I'll 'prove' to you that I can power a country from unicorn droppings, all the way from North Korea...
Re: Let's do it.
The obvious weakness, from a British point of view, is that the USA is big. This may well work out for mainland Europe, but the variations in weather over the UK may not be enough to keep everything going.
It isn't hard to see the other assumptions, but I think this is done well enough to be a counter to "we can't afford it". A power plant built today will be needing replacement by 2030. Whatever the replacement is, it will cost money. And renewables, done right, look a plausible choice.
But this sort of large-scale planning isn't something that a fragmented, privatised, electricity generation system is likely to do well.