Tuesday, February 22, 2011

How the Western US can implement large-scale implementation of wind and solar power

Most of us desire a clean environment, and desire electricity to be generated with no negative consequence. As it stands electricity generation has huge negative consequences from the coal emissions, to the mining operations to get the coal, to disposing of the coal residues, and the CO2 etc emitted from burning natural gas. It's a bad story that can be fixed through using more wind and solar energy. But wind and solar needs some sort of energy storage to balance out variability and the troughs in production.

Debra Lew, of the National Renewable Energy Laboratory, gave a presentation at the Energy Seminar at Stanford University discussing models for how the Western US could adopt large quantities of wind and solar energy. One conclusion they came to is that large scale energy storage systems aren't as necessary as conventional wisdom would believe.

Wind power - mostly occurs at night - Solar power - mostly occurs during the day. Hence the simple assumption is you need to store energy from when generation is at its peak production and release stored energy when it's in a trough. That is, next to the wind farm you install an energy storage system that fills up overnight, and releases energy during the day.

However.. Ms. Lew says this isn't necessary, if the grid operators make some changes to how the business is run.

Observation: Wind and solar energy complement each other. One has its peak when the other is in a trough. Hence energy storage isn't required so much as having enough generating capacity. A factoid about energy storage systems is they're currently rather expensive. The grid operators will want to minimize energy storage systems, and the cheapest way to do so is to not buy it but instead by enough wind/solar generating capacity so that one system makes up for the other system's trough.

The Western US is covered by WECC which is an electrical interconnect zone. In most of WECC there is little cooperation between the utilities, leaving each utility on its own to balance its load.

Ms. Lew gives regional "balancing area cooperation" as a primary change to implement for renewable energy to make a big impact in the West. For example Wyoming has huge wind resources, and could be supplying electricity to the rest of the West if only there were enough cooperation and transmission lines.

She gave a bunch of other recommendations. The whole pile of them boiled down to: greater flexibility

Their study shows it's operationally feasible for the Western US to adopt Wind and Solar at a large scale.

She did say that historically this region has tried to set up more cooperation but ran into political problems. Essentially the individual utilities have resistance to their autonomy being undermined by a regional cooperative. But she went on to say that as they get more experience with renewable energy they'll realize regional cooperation is vital.


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