Existing Grid sufficient for a little while: NREL
October 29, 2010 by Paul Dvorak
Filed under Utility Grid, Wind Power News, Wind Watch
NREL says more than a third of the electricity in the western U.S. could come from wind and solar power without installing significant amounts of backup power. And most of this renewable-energy expansion can happen without installing new interstate transmission lines, according to a recent study from the National Renewable Energy Laboratory (NREL) in Golden, Colo. But, says NREL, increasing the amount of renewables on the grid will require smart planning and cooperation between utilities.
The NREL findings provide a counterargument to the idea that the existing power grid is insufficient to handle increasing amounts of renewable power. As California and other states require utilities to use renewable sources for portions of their electricity, some experts warn that measures to account for the variability of wind and solar power could be costly. At the extreme, they speculate, every megawatt of wind installed could require a megawatt of readily available conventional power in case the wind stopped blowing. But the NREL findings, like other recent studies, suggest that the costs could be minimal, especially in the West.
“The studies are showing the costs are a lot lower than what people thought they were going to be,” says Daniel Brooks, project manager for power delivery and use at the Electric Power Research Institute. Even if wind farms had to pay for the necessary grid upgrades and backup power themselves, they could still sell electricity at competitive rates, he adds.
NREL
Large electrolysis units could stabalize the grid and more
August 3, 2010 by KRemington
Filed under Wind Power News
The best way to store the wind-generated power is anyone’s guess. The equipment for one idea comes from Toronto-based Hydrogenics, a firm that manufacturers industrial electrolysis units, devices that separate hydrogen from oxygen in water. Hydrogen can be used in industrial applications, but the company suggests storing it as a vehicle fuel and provides several examples of city busses that could use it as well.
Hydrogenics’ HyStat 60 consumes about 365 kWh to product 60 m3/h of hydrogen. Storage and dispensers are not shown.
That’s not all, says Robert McGillivray, the company’s director of renewable energy. “Electrolyzers operate over a wide range of capacities from 10% to 100% of rated load for large, multi-stack systems. And they can quickly ramp up and down without adverse effects. That means the units could come on and off line quickly to provide load to the grid when necessary and drop off when daily demand grows as it does around sunrise.”
With storage, as would be needed for fueling stations, electrolysis can operate at times that vehicles don’t need fueling. The vehicles could be cars but more likely they would be city busses powered by fuel cells. (GM and others have announced that 2015 could be the year that fuel cell powered cars go on sale. The company also recently showed off its Gen2 fuel cell.) The interest from this magazine is that the electrolyzers could be powered by wind energy.
McGillivray says the company’s HySTAT line of electrolysis units is modular with building blocks of 365 kW capable of generating 60 m3 of hydrogen per hour. Multiple systems could work at a site to consume 1 to 5 MW. Larger systems could consume 10 to 100 MW. The hydrogen generator is containerized and available with a compression, storage, and dispensing package to match the needs of the vehicle fleet. The idea is that hydrogen would be produced when needed and on site rather than pumped from miles away.
McGillivray says there are over 150 fueling stations around the world supporting demonstration programs for buses, cars, and vehicles such as forklifts. A fleet of 100 municipal buses would consume about 3.8 tones of H2/day given typical bus routes. If supplied by electrolysis, this would represent about 10 MW of continuous load.
The company has provided electrolysis equipment for over 35 fueling stations worldwide including one program in Europe and stations in California supporting bus and car fleets. Fueling stations and their load could be in several locations allowing control of the grid to address transmission constraints as well as load balancing. WPE
Study explores role of grid technologies in growth of U.S. wind energy
July 16, 2010 by Paul Dvorak
Filed under Policy, Utility Grid, Wind Watch
A recent report, Business Strategy: Optimizing Transmission for Wind Integration examines the role of key transmission technologies essential for the rapid growth of the U.S. wind energy market. The report (Document # EI223579, June 2010) from IDC Energy Insights, Framingham, Mass., (idc.com) describes the impact of current transmission constraints on existing and planned wind farms and the challenges encountered to proposals of new transmission lines.
Five grids at different voltages connect the U.S. The IDC Energy Insights study includes an overview of transmission technologies that offer solutions to the challenges along with examples and an analysis of the strengths and weaknesses of each approach. Map source: EIA
“Wind-based electricity generation has enjoyed rapid growth in the U.S. over the past 10 years, driven by state-level renewable portfolio standards and wind’s current status as the least cost, most scalable renewable energy option,” says IDC Energy Insights Research Manager Jay Holman. “New wind farms must be located in areas with excellent wind resources and, unfortunately, these areas are often far from load centers and have weak transmission infrastructure.”
According to the IDC Energy Insights study, this creates a well documented need for additional transmission capacity, which has been difficult to satisfy due to planning and permitting hurdles that can cause endless delays and cost escalations for new transmission projects.
However, IDC Energy Insights research indicates it is not always necessary to build new transmission lines to add transmission capacity. Technologies exist that allow an increase in transmission capacity that causes little or no visible change to the existing transmission infrastructure. Even in situations where new transmission lines are required, technologies are available that can minimize their footprint, helping to stimulate planning and permitting. While no single technology will solve all transmission related challenges, together these technologies will play an important role in increasing the penetration of renewables – wind in particular – on the grid. The technologies cited by the report include:
• Dynamic line rating
• High-temperature, low-sag conductors
• Voltage uprating
• Ac-to dc conversion
• Flexible ac transmission equipment
• High-voltage dc equipment
• Superconducting conductors
“The costs that transmission constraints have imposed on the energy industry through wind curtailment and wind project delays, cancellations, and size reductions have led to increased focus on technologies that can quickly and economically increase transmission capacity while helping to alleviate challenges associated with the planning and permitting process,” says Holman.
The IDC Energy Insights study includes an overview of transmission technologies that offer solutions to the challenges along with examples and an analysis of the strengths and weaknesses of each approach. Finally, the report draws conclusions and makes recommendations for industry stakeholders who want to take full advantage of existing and planned transmission technologies.
