A key challenge for wind and solar systems is intermittency. The wind isn’t always blowing and the sun isn’t always shining. But, in many parts of the world, this presents an opportunity for complementary systems — as the wind is often blowing when the sun is not at peak and vice versa. Combining these systems can enable higher probabilities of providing year-round power while (potentially) requiring lower storage requirements (in size, complexity, cost, …) and/or limited “traditional” fuel backup systems.
Motorola is going to be testing this combination as an alternative to diesel generation for off-grid sites.
The diesel-free power system is been positioned as a green alternative to using fuel generators when a main grid connection is not available or it will take months or years to connect. Motorola says the technology has applications in both the developed and developing world. Western operators might be interested in the technology as a way of reducing their carbon emissions and of reducing operational costs, especially as electricity prices are expected to rise between 30-40 per cent over coming years.
Wind and solar powered stations require less maintenance than a diesel driven generator which generally requires, at a minimum, a monthly visit for refueling. Thomas Quirke, director of marketing at Motorola, said that diesel power is expensive, especially in cases where it needs to be delivered to cell sites without road access, and often gets siphoned off. “Diesel fuel supplies are heavily prone to theft. Thieves will even take diesel generators, given the chance,”
And, here is a classic “cost to buy” versus “cost to own” equation. “Diesel generators remain cheaper to install but this is offset by higher operating expenses.”
Also, this points to the importance of systems-of-systems thinking. The cost factor isn’t just what it costs to buy, but the full cost to own — including the purchase price, fuel cost, maintenance requirements, system replacement, theft, etc … In the total, the solar/wind combo seems to blow the diesel away, even if the diesel seemed “cheaper”. Now, of course, one of the problems that we have, writ large, is to include externalities (air pollution) into this cost discussion — but that is for another time.
We might just see Africa sprinkled with solar/wind combination systems supporting the proliferation of cell phones throughout the continent.
This combo application, however, is far from limited to just cell phone transmission.
Skybuilt Power has a mobile power station, that combines wind and solar power moved inside a container that, after the system is set up, could be used for other things (like an office, a clinic, or ???):
- Containerized, rapidly deployed power, expandable from 0.5 kW to150 kW or more; use the inside of the container for any purpose in the field
- Power without fuel and virtually no maintenance
The US military is buying some of these and deploying them to bases in Iraq.
The effect of the Pentagon’s interest in conservation and alternative energy can be seen from military bases and hangers to the battlefields of Iraq and Afghanistan. In late July, Marine Corps Maj. Gen. Richard Zilmer, commander of U.S. forces in Iraq’s insurgent al-Anbar province, asked for a shipment of mobile solar panels and wind turbines to supplement gas-guzzling generators at bases under his command.
Cutting “the military’s dependence on fuel for power generation could reduce the number of road-bound convoys” and U.S. casualties resulting from insurgent attacks on U.S. supply convoys, Gen. Zilmer wrote in a memo. The Army’s Rapid Equipping Force, the unit responsible for processing such requests, has contracted SkyBuilt Power of Arlington, Va., to build four hybrid power stations for delivery this spring.
There is, to me, no such thing as a silver bullet solution to our energy and global warming challenges — not nuclear power, solar, wind, energy efficiency, and otherwise. What we require are a good number of silver pellets. 
It seems that this combo — wind and solar — points at a pellet. That using complementary systems, in tandem, can help create a full-spectrum solution outside the capacity of each individual “silver pellet”. Could a wind/solar/biomass combination provide, for example, a total solution to energy requirements in some communities? Eliminating the requirement for traditional fossil fuel energy systems? Seems to me that they could …