Three far-reaching British energy bills became law last week, making the U.K. the first country in the world to introduce a legally-binding framework to cut greenhouse gas emissions while enacting other policies that should spur the adoption of clean technologies.

But a leading U.K. energy adviser said the legislation will drive up the cost of electricity and gas and force families to spend larger portions of their income on utility bills.

One piece of legislation, the Climate Change Bill, commits the U.K. to reduce by 2050 greenhouse gas emissions by 80 percent from 1990 levels. Between now and then, the government will introduce five-yearly “carbon budgets” outlining how emissions targets will be met and phase in plans for corporate emissions reporting.

The legislation also calls on the government to implement a system of feed-in tariffs for small renewable energy producers by 2010. Feed-in tariffs guarantee that the owner of a renewable energy system will be paid at fixed prices by utilities for electricity fed into the grid.

The growth of solar and wind energy in Continental Europe, especially in Germany, France and Spain, is widely believed to be largely a result of ambitious feed-in tariff policies. Britain’s energy legislation limits feed-in tariff projects to no more than 5 megawatts, and there are no specific provisions yet on prices, according to a Renewable Energy World report.

According to the U.K. government, the second piece of legislation, the Energy Bill, will drive development of new civil nuclear power, expand the use of renewables, and pave the way for new technologies such as carbon capture and storage and smart meters. The final legislsation, the Planning Bill, addresses energy efficiency in homes and simplifies planning permission for all large energy infrastructure projects, said a government summary.

Meanwhile, Britain’s chief climate change adviser, Lord Adair Turner, said in a recent speech that reducing emissions on the scale required by the new legislation could push more than 1.7 million houses into so-called fuel poverty, when families spend more than a tenth of their income on energy. The cost of electricity and gas is expected to rise as utilities are forced to invest in renewable energy and other clean technologies to meet emissions requirements.

Lord Turner said, however, that many of these families could be helped to avoid fuel poverty through grants or subsidies that pay for energy efficiency improvements in their homes.