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
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.
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
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
panel 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 tie inverter , it could be calm and overcast in another and all parts of the grid
would have enough power.
没有评论:
发表评论