Geothermal power generation using water is problematic.  Why?  Because water is in very short supply.  Sending it down drill holes into hot rock fractures to make steam uses too much.

Closed systems where the water is recovered need large heat exchangers at the top after the steam has gone through turbines.  Using glacier melt to cool it, or using a refrigerant gas instead of water in the turbine?  This gets really expensive.  And very difficult to locate.  Iceland has the underground heat and ice to do it.

For the rest of the world wind power is a lot cheaper, and it doesn't use water or melt glaciers.  Wave power is coming along too.  So is solar.

But to save a large percentage of the huge amount of energy used to heat/cool buildings, geothermal IS the answer.  That 50 degreee heat sink underground can cool buildings with fluid circulation.  And defer heating buildings in cold climates with a 50 degree heat envelope created with circulated fluid.  It is like placing a building underground in terms of heating load.

When it is 50 degrees outside hardly any heat is needed to keep a building at 65 degrees inside.  The waste heat from appliances will do it, even if the appliances are very efficient.  Or even if solar hot water supplements a regular hot water system.

In some rare cases of extremely efficient, low power use homes, in areas with little solar insolation, a heat pump maybe necessary for home heating.  It would extract heat from the geothermal heat sink and operate at very high efficiency and very little power would be needed to run it.

This kind of heating/cooling using the earth itself as a geothermal heat sink would reduce energy use enough so that renewables could power transportation and the rest of energy demands.

I'm surprised to see that old talking point about huge amounts of storage needed to backup wind and other renewables.  I thought Gar had put that to rest.

Maybe you should reprise that one Gar, along with the latest data on wind farms on a widely distributed grid.  

I like biogas/fuel cell for backup instead of storage.  It saves huge amounts of GHG that otherwise are released from and by the wasate stream.  The organic fertilizer produced saves a whole 'nother huge amount of GHG.

Don't fall for plans to replace the huge waste of energy that coal power now feeds.  Reduce energy consumption with conservation using geothermal heating/cooling and plugin transportation, then get that reduced amount of energy from renewables.  Backup the distributed renewable grid with biogas/fuel cell.

It will work without nuclear power or geothermal steam turbines.  Water is very scarce and precious, do not pollute it with nuclear leaks and waste seeping into groundwater or metal acid bearing rock from geothermal.  

Besides which these two sources are way, way too expensive and will be run by the same old corrupt government/non regulated contractor cabal that has brought US oil wars and GHG disaster to benefit their bottomline.

Distributed renewable energy and conservation are built up with a lot of local jobs and build our manufacturing and tax base with them.  And just maybe we can get auto companies to build plugin vehicles here in the good old USA?  I bet we could.

And don't forget biogas, it can convert present chemical agriculture to organic, providing another whole host of economic recovery with the restoration of smaller family farms and farm communities where they become small distributed renewable energy suppliers as well.