> Renewable energies are very annoying to grid operators. Their energy production is unreliable,<p>I don't know if the people involved find it annoying though I doubt it. But the second assertion is flat out untrue.<p>It is not unreliable, it is reliable but intermittent. Wind power availability can be fairly well forecast.
The imputed comparison between hydrogen electrolysis and battery storage is not apples-to-apples:<p>- The hydrogen numbers are from a Fraunhofer (vendor) report. They discuss the cost of the components of the electrolysis system itself.<p>- The battery numbers are from an EPA report. They include the total cost of batteries as a line item ($200/kWh), and go on to add in permitting, construction, grid hookups, land acquisition, etc.<p>Unsurprisingly, a regulatory agency analysis of system cost is more pessimistic than a vendor's analysis of product cost.
Flywheels are an alternative to batteries for grid stability. Very little interest in adding them due to the continued advancement of batteries. I'm actually surprised how often they're missed as a viable solution.
Does this show that current markets are working? Seems like the lowest cost energy storage solution are NG peakers, and it does seem like the US has a lot of gas energy production: <a href="https://www.eia.gov/tools/faqs/faq.php?id=427&t=3" rel="nofollow">https://www.eia.gov/tools/faqs/faq.php?id=427&t=3</a>
Could residential hydrogen generation, storage, and use be viable? Say you have solar, a water supply, and a big hydrogen tank. Any excess electricity can make hydrogen by electrolysis and store it to be used for heating and cooking. No expensive transport or exotic fuel cells. In arid climates the water vapor from burning it could even be captured.<p>The two big problems I see are that hydrogen is trickier to pipe than natural gas, and if there is no hydrogen economy to make backup deliveries, how do you keep up with essential heating when there isn't much excess electricity?
It seems that freshwater pumped water storage could be one of the most cost-effective options especially paired with batteries for peaking. Adding it to the analysis would be useful.