Found an interesting article today (via EcoGeek) from which I take the following quotes:
"Baseload is what those older technologies provided, not what we need... We need something that follows the natural load."
In other words, the grid is currently constructed to accommodate capital-intensive fossil fuel plants that need to run 24/7 to be most efficient and economical. The natural load, on the other hand, is the demand for electricity created by people's and the economy's daily rhythm. That demand naturally peaks when people are up and about and falls at night when they're asleep. Renewable energy sources, Mills argues, more closely mirror human behavior. Solar electricity production soars when demand does during the day. At night, stored solar energy and other renewable sources like wind, which tends to blow strongest in the evening, can more closely match lower demand as people and machines wind down.
Those of us who wish to support the expansion of the renewable energy industry need to counter the argument that renewables cannot supply sufficient baseload power. Perhaps we should be pointing out that the demand for such high power consumption overnight has been artificially generated to suit the coal-fired power stations.
But I'll also take that as justification for my decision to invest in a solar water heater even though it doesn't appear to make economic sense under current conditions. By reducing our night-time electricity consumption I'm ever so slightly changing the demand curve and eroding the argument that we need technology which can provide such large amounts of energy 24 hours a day.