In the old Aesop fable, wind and sun battle over which is the stronger. The wind blows hard, but the sun shines hot. They both do their best to get a traveler to remove his jacket. In the fable, sun wins. But in real-life policy questions over solar power and wind energy -- over which provides the more cost-effective source of clean energy -- it appears that wind has sun on the ropes. At least for the moment.

Both provide an environmentally friendly alternative to coal- and gas-fired electricity, and both emit none of the greenhouse gases associated with global warming. But solar power -- despite several advantages over wind -- is much more expensive, say experts. "You get more bang for your buck from wind energy than from solar energy," said Ryan Wiser, who leads renewable-energy research at the Lawrence Berkeley National Laboratory in California.As the public expresses growing concern over both global warming and rising utility bills, consumer advocates say it's more important than ever to balance the costs and benefits of wind power, solar power and other forms of renewable energy.

It's not a question of whether the state should pursue clean-air strategies -- but rather which ones, and at what cost. Who stands to save money and who stands to pay more? Is nuclear power part of the solution?

No major state agency -- not the Texas Public Utility Commission, not the Texas Commission on Environmental Quality -- has been tasked with coming up with a comprehensive renewable-energy policy that balances the state's clean-air needs with consumer interests within the context of the state's deregulated electricity market. However, House Speaker Tom Craddick has created a special committee to study the state's long-term energy needs, as well as the effect of new power generation on global warming.

The Texas Public Utility Commission will take on some of the issues piecemeal in the coming months.

Sun vs. wind: Round 1

The solar-power industry already lags far behind wind in Texas, which recently leapfrogged over California to become the largest wind-power-generating state in the nation. And many more wind turbines are expected soon thanks to an aggressive and expensive plan at the PUC to build more transmission lines.

But California leads the nation in solar power and is pursuing even more through its Million Solar Roof Plan, which was signed into law by Republican Gov. Arnold Schwarzenegger in 2006.

A look at those two programs in both states provides useful points for comparison.

In California, the plan is to provide new publicly funded rebates for those who install solar panels at their homes and businesses. California is charging ratepayers about $3.3 billion -- or about $86 per Californian -- to finance the program. That amounts to about $1 per month on a typical bill over a period of years, according to a representative of the California Public Utilities Commission.

Policymakers say the rebates will increase California solar power output by 3,000 megawatts by 2018 -- or enough new power for about 1.5 million homes, under normal conditions.

By comparison, the Competitive Renewable Energy Zone program in Texas will lead to the construction of $3 billion to $6.4 billion in transmission lines -- all for wind power, and all constructed at ratepayer expense. That equates to anywhere from $150 to $320 for every Texan served by the state's power grid, although the exact impact on home bills won't be known until action later this year by the Texas Public Utility Commission. The cost will likely be spread over a number of years.

Under the Texas plan, the state hopes to encourage electric companies to build an additional 5,150 megawatts to 17,950 megawatts of wind turbines -- or enough for 2.6 million to 9 million homes.

Bottom line: Under the California plan, the development of an additional megawatt of solar power would cost ratepayers $1.1 million. Under the Texas plan, an additional megawatt would cost $356,000 to $573,000.