Doe also doing demonstration projects on energy efficient buildings wind power solar power and geothermal heat pump technology.

美国能源部还做的示范项目有：节能建筑，风能，太阳能，地热收水技术。

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Last year, three geothermal power projects submitted bids under the program, and only one won a contract.

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Its calculations do demonstrate that power generation projects that use solar panels and geothermal technologies will be cheap enough to start to replace coal by 2030.

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