The virtue of solar is that it tends to perform optimally during those times when electricity consumption is at its peak. During the day - particularly hot days - when people are working, factories are making things and air-conditioning systems are humming along, it is nice to know there is a reliable source of power at hand to keep everything up and running, particularly under the specters of brownouts and outright outages.

Moreover, solar power systems, by and large, can be placed relatively close to the source of loads, which enlightened utility planners can use to defer capital expenditures in large-scale generation plants and transmission and distribution infrastructure.

Solar also has the advantage of being as close to a solid-state technology as you are going to find in the power generation world. The lack of moving parts simplifies maintenance. There’s no water to boil (with PV, anyway), no turbines, no pressure vessel.

Moreover, waste discharge into the environment isn’t an issue - unless you count glare, and even glare can be handled with effective site planning and cooperation with the community and aviation authorities.

And yet time and again, advocates of solar technology run up against the energy storage issue. Without an energy storage component, solar is simply unable to provide electricity during times when the sun is not available - at night or during periods of persistent overcast. Without storage, solar is relegated to a supporting role in the grid.

“The stage is not yet set for storage,” says Paul Winnowski, president and CEO of Mainstream Energy Corp. “Solar is great technology for strengthening the grid, but we are still a ways out from the storage component being widely available.”

This is too bad. According to Sam Chatterjee, director of project finance at developer Borrego Solar, storage would completely change the market for solar power in the residential and commercial spaces. “Other components are getting cheaper,” he says. “Cheap storage would be a game changer.”

Just like the electric vehicle industry, it always comes back to those damn batteries.

There are people working on developing what would become solar’s killer app. Next time you go to a solar trade show, take the opportunity to visit the storage people. Encourage them. Be nice. We need them. S