by kublikhan » Sun 03 Mar 2013, 02:05:16
I also disagree with the Huffington article. Energy storage is not the only option for addressing the intermittantancy of solar/wind. There are others:
1. overhaul the transmission grid to increase the ability to redirect surplus power from one region of the nation to another part of the nation, and/or neighboring nations. We need a truly national grid instead of the various regional grids we have now. That way when one region of the grid has a power sag because of intermittant solar/wind, another region can step up and fill the gap.
2. use conventional power plants as peaker/backup plants. Keep a few natural gas/quick start coal plants in mothballs and power 'em up when the wind stops blowing or the sun stops shinning. It's actually cheaper to keep a few of these plants around for backup power than it is to build a giant national grid battery. You don't need a 1-1 GW for GW backup for renewable either. Just make sure you can reroute the power to the part of the country that needs it.
3. power demand fluctuates and is not uniform. Yet the power grid must be able to supply the maximum amount of energy demanded. This leads to so called "peaker plants" that operate only when demand is highest and are idled the rest of the time. Because solar produces electricity when demand is highest(midday), it reduces the need for building new new peaker plants.
4. Implement a smart grid with a high degree of demand response. Ex: staggering ac use when the grid starts to peak, run appliances at night when power is cheap, program EVs to charge only during demand sags when power is cheap, reduce energy intensive industries during peak loads, etc.
$this->bbcode_second_pass_quote('', 'D')uring one 24-hour period, Germany’s PV accounted for nearly a third of the nation’s energy needs on midday Friday when the nation’s factories and offices were humming along, and then it approached 50 percent midday Saturday as residents enjoyed a sun-filled weekend.
According to the International Economic Platform for Renewable Energies in Muenster, the power produced at its weekend peak was greater than the capacity of 20 nuclear power plants. The timing of the peak is particularly important since it comes during times when energy use is at its highest.
"It is often underestimated that the sun brings significant power if and when it is needed most. In the peak time for lunch," said institute director Norbert Allnoch. Because of this, the group says that expensive peak load power plants are increasingly rare or no longer used.
Germany's Day in the Sun: Solar Hits 22 GW Mark$this->bbcode_second_pass_quote('', 'E')RCOT found that if you use updated wind and solar power characteristics like cost and actual output to reflect real world conditions, rather than the previously used 2006 assumed characteristics, wind and solar are more competitive than natural gas over the next 20 years. This might seem a bit strange since we’ve been told for years by renewable energy skeptics that wind and solar power can’t compete with low natural gas prices.
Facing an acute energy crunch and given that solar and wind costs have come down a great deal since the first study in 2006, ERCOT dug a little deeper into their historical assumptions and developed a version of the model that used current, real-world cost and performance data for wind and solar power. What they found was astounding: without these real-world data points, ERCOT found that 20,000 MW of natural gas will be built over the next 20 years, along with a little bit of demand response and nothing else. Once they updated their assumptions to reflect a real-world scenario (which they call “BAU with Updated Wind Shapes”) ERCOT found that about 17,000 MWs of wind units, along with 10,000 MW of solar power, will be built in future years.
In addition to demonstrating the economic viability of renewable energy, these results show two drastically different futures: one in which we rely overwhelmingly on natural gas for our electricity, and one in which we have a diverse portfolio of comparable amounts of renewable energy (which does not use water) and natural gas. All of this is crucial to keep in mind as the Legislature, Public Utility Commission and ERCOT evaluate proposals to address resource adequacy concerns and the impacts of a continuing drought on our state’s energy supply.
Finally, one ERCOT statement in particular stands out from this analysis, in direct contradiction to renewable energy opponents who say that renewable energy is too expensive: “The added renewable generation in this sensitivity results in lower market prices in many hours [of the year].” This means that when real-world assumptions are used for our various sources of power, wind and solar are highly competitive with natural gas. In turn, that competition from renewables results in lower power prices and lower water use for Texas.
As state leaders look for ways to encourage new capacity in the midst of a drought, it’s important to realize that renewable energy is now competitive over the long term with conventional resources. The fact that renewable energy resources can reduce our water dependency while hedging against higher long-term prices means that however state leaders decide to address the energy crunch, renewables need to be part of the plan.