Mid-May proved beneficial for many high-voltage transmisison developers, as the Federal Energy Regulatory Commission’s “high-voltage gravy train” kept delivering the cash. Five additional transmission projects received incentives, including bonsues to the project’s return on equity or rate recovery during construction. Earlier this year, I wrote about FERC’s program of incentives for new transmission projects, noting… Continue reading
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The solution to the variability of wind power is more wind.
The output from a single wind turbine can vary widely over a short period of time, as wind goes from gusty to calm. The adjacent graphic (from this report) illustrates how a single turbine in Texas provided varying power output over a single day, varying from under 20 percent of capacity to near 100 percent!
But the same report also illustrated the smoothing effect when the output from these five wind sites was averaged. The following chart shows (in dark orange), the smoothing effect of output when the wind output was averaged over five sites.
The impact is significant, and the optimized system varies from 15 to 50 percent of capacity, compared to individual turbine variability that’s twice as large. Over a longer period (a year), the optimized (combined) system provides significantly more reliable power to the electric grid. It reduces periods of zero output to a few hours per year, effectively zero probability.
Combining the output of the five sites also increases the probability that the output will be at least 5% or 10% of total capacity of the wind turbines.
Other studies have reinforced these findings. For example, a report by Cristina Archer and Mark Jacobson in 2007 found that dispersing wind at 19 sites over an area the size of Texas increased the level of guaranteed output by 4 times.
Wind power could not be the sole source of electricity for the grid without massive overbuilding of capacity, but its variability is an argument for more dispersed wind, rather than less of it.
An oxford-style debate hosted by the Information Technology Innovation Foundation in Washington DC. Jim Baller and Christopher Mitchell defend local authority to build community networks over the course of a two hour debate. This is an excellent policy discussion. Continue reading
Despite the ample publicity Wal-Mart has engineered for its "buy local" efforts, the company in fact has zero interest in cultivating local suppliers beyond stocking a few token local veggies suitable for a nice photo-op. Continue reading
I just got a copy of a utility bill for a Minnesota business that has a 40 kilowatt (kW) solar PV array. I’d hoped to get a sense for how quickly he’d pay off his array with the net metering revenue. I was shocked. Payback time was 30 years. Even if the business owner had… Continue reading
John Farrell is on leave to spend some quality time with his new daughter. Look back June 6 for more great distributed generation content and an announcement of a new report on distributed generation!
We’ll give you some time insensitive material this week we’ve been saving.
Power plants use a stunning amount of water. In 2005, thermoelectric power (e.g. coal, natural gas) accounted for half of all water use in the United States. Across the country and particularly in the arid West, the water savings from renewable energy are as important as the pollution-free energy.
That makes the distinction in water use between centralized solar and decentralized solar a big deal, especially since centralized solar is only planned for the dry Southwest.
The following graphic illustrates water consumption for common types of power generation per MWh of electricity produced (additional reference here):
Traditional power generators are water hogs. For example, a nuclear power plant consumes 720 gallons of water for each megawatt-hour of electricity produced. Powering a single 75-watt incandescent light bulb for an two hours on nuclear-generated electricity would consume 14 ounces of water (more than a can of pop).
While most of that water is returned to the environment, this report by the Alliance for Water Efficiency and ACEEE notes that it’s not undamaged:
Water is returned to its original source, even though its qualities have changed, especially temperature and pollutant levels.
Nuclear and coal may be big offenders, but wet-cooled concentrating solar power uses even more water per MWh of electricity generated. Dry-cooled CSP cuts water consumption significantly, but it’s still far more than solar power from photovoltaics (or wind power).
If it were solely a question of cost, CSP and PV come out relatively close (see updated chart below) despite the former’s frequent need for transmission access.
But if the tradeoff is significant water consumption versus none, then decentralized PV may make more sense everywhere, including the sunny Southwest.
Photo credit: Flickr user Shovelling Son
Some nice news from Connecticut, where the state’s commitment to increasing distributed generation is increasing on-site generation and helping hold rates down:
Distributed generation is becoming more popular in the state and throughout New England, especially among businesses foreseeing the financial and environmental benefits of decreasing their reliance on the electric utilities.
As a result, the regional grid will be comprised of fewer large commercial ratepayers and more small business and residential ratepayers. The long-term effect will dampen rates, said Phil Dukes, spokesman for the Connecticut Department of Public Utility Control.
A business generating its own power decreases the overall need for electricity on the New England power system. When the peak load drops, the regional system needs less electricity and eliminates its use of the most expensive power plants. These peaker plants tend to run inefficiently and burn less environmentally-friendly fuel, Dukes said.
“There is certainly more upside than downside to distributed generation,” Dukes said. “That is why the state has invested so heavily in it.” [emphasis added]
In a press release earlier this week, WWEA released this definition of community power alongside a new study on the public acceptance of community-owned wind:
A project can be defined as Community Power if at least two of the following three criteria are fulfilled:
1. Local stakeholders own the majority or all of a project
A local individual or a group of local stakeholders, whether they are farmers, cooperatives, independent power producers, financial institutions, municipalities, schools, etc., own, immediately or eventually, the majority or all of a project.
2. Voting control rests with the community-based organization:
The community-based organization made up of local stakeholders has the majority of the voting rights concerning the decisions taken on the project.
3. The majority of social and economic benefits are distributed locally:
The major part or all of the social and economic benefits are returned to the local community.
The press release also references this recent study of community ownership that we covered last week: Community Ownership Boosts Support for Renewables.
Yet another Canadian province is showing a serious commitment to the economic benefits of renewable energy development. Ontario’s “buy local” energy policy has the promise of 43,000 local jobs from 5,000 MW of new renewable energy. Now Nova Scotia is completing rulemaking for a provincial goal of 40% renewable power by 2020 that includes a 100 megawatt (MW) set-aside for community-owned distributed generation projects. The policy promises to increase the economic activity from its renewable energy goal by $50 to $240 million. Continue reading