The non-profit Next Gen Energy Council said they could be worse than the energy crisis California faced in the summers of 2000 and 2001.
According to the report, if California experiences an unusually hot summer, local blackouts could cascade into regional disputions.
Next Gen said reserve energy supplies have declined from around 35 percent in the early 90s, to just 17 percent today.
The group blames what it calls, "well-funded environmental groups" for blocking new power plant projects.
