Here's the updated Stanford study
Avoiding blackouts with 100% renewable energy | Stanford News
They analyse three different scenarios. Some use heat storage.
Relevant section of original study.
Matching Electric Power Supply with Demand
... In that study, it was found that matching large differences between high electrical
demand and low renewable supply could be realized largely by using a combination
of either (1) substantial CSP storage plus batteries with zero change in existing hy-
dropower annual energy output or peak power discharge rate, (2) modest CSP stor-
age with no batteries and zero change in the existing hydropower annual energy
output but a substantial increase in hydropower’s peak discharge rate, (3) increases
in CSP-storage, batteries, and heat pumps, but no thermal energy storage and no
increase in hydropower’s peak discharge rate or annual energy output, or (4) a com-
bination of (1), (2), and (3).