Its not stealing; its borrowing without permission. But thankfully, the sun will never miss it.

Solar-powered heating systems are taking the world by storm or rather, by drought and heat. In the warmer climates, technophile homeowners are mounting high-tech photovoltaic (PV) silicon solar cells onto their rooftops to seize sunrays, and their more middle-class or financially savvy counterparts use solar hot water systems to capture the suns heat and warm their water. Affordable, effective, versatile and scalable, these systems are quite the talented thieves of the sun.

Solar hot water systems (SHWs) begin life as little more than water-filled, black-painted tanks tackily tacked onto rooftops. But by adulthood, these domestic heating systems come in a myriad of categories.

Simple systems, which rely on convention, heat and gravity to circulate water, are labeled passive (or compact). Their technophile-oriented siblings, active (or pumped) systems, use mechanical controls and pumps for circulation.

The black-tank SHW method is an example of a direct (i.e. open loop) process, where the sun heats water directly; indirect (i.e. closed loop) systems utilize a heat-transfer fluid which, after solar warming, then heats water.

All SHW systems contain two basic elements: a solar collector, which receives the suns heat; and a water tank, which is hopefully self-explanatory. An Integrated Collector Storage (ICS) system (i.e. batch heater) fuses these two elements together. Water is warmed in a tank, where, due to its new-found heat, it rises to the apex of the tank and, under convection forces, streams into a pipe and onto a toothbrush, finger, or dirty dish. Its arch-nemesis, the thermosyphon system, keeps the solar collector and water tank separate. Water is passed through pipes into the solar collector, where it is heated, and then continues on its merry journey.

Whew and these are just the basics. Types of solar collectors (i.e. flat-plate or evacuated-tube), construction of pipes, shape and position of water tanks, are other variables. Moral of the story: before buying a SHW, talk to a qualified technician, engineer or other service.

But that pivotal question still remains: why buy?

SHWs are a homeowners silent protest against the ensconcing of superfluity, gratuity, and frittering in society. Waste runs rampant as fossil fuels exert their omniscient power over humanity. Tired of puppet strings? Using renewable energy, such as SHWs, cuts the ties of fossil fuel bondage, reduces energy dependency, drastically decreases pollution, and privatizes energy.

But lets take our heads out from the clouds for a moment. Changing the world is great, but what does God, er, the wallet, have to say? SHWs cost - the cost of PV cells, and are eligible for a 30% total price reduction due to Federal tax incentives. According to Solar Direct, some solar water heaters may cost as little as 10% of conventional gas-powered systems. Ka-ching; the wallet smiles.

And for the direst query of all: what happens in winter? The answer is simple. SHWs dont work; which, if precautions are not taken, leaves the homes inhabitants freezing. Therefore, SHWs generally employ supplementary back-up heaters, powered by natural gas or electricity, to shoulder the burden during cold nights or winter months.

The sun has enough for everyone. Accept its gift; install a solar-powered hot water system; reduce energy dependency; and keep the wallet happy.