Article failed to mention that wind/solar storage can be usefully teamed-up with the another (renewable) energy source, the heat in the ground ... which is near

Article failed to mention that wind/solar storage can be usefully teamed-up with the another (renewable) energy source, the heat in the ground ... which is nearby many of our houses. Today's heat pumps can work well for many down to outdoor temperatures of about 5 degrees F (-15C). They'll bring down the cost of using the other sources. [https://www.youtube.com/watch?v=MFEHFsO-XSI https://www.youtube.com/watch?v=MFEHFsO-XSI]