China is planning a vast increase in its use of wind and solar power over the next ­decade and believes it can match Europe by 2020, producing a fifth of its energy needs from renewable sources, a senior Chinese official said yesterday.

Zhang Xiaoqiang, vice-chairman of China's national development and reform commission, told the Guardian that Beijing would easily surpass current 2020 targets for the use of wind and solar power and was now contemplating targets that were more than three times higher.

In the current development plan, the goal for wind energy is 30 gigawatts. Zhang said the new goal could be 100GW by 2020.

"Similarly, by 2020 the total installed capacity for solar power will be at least three times that of the original target [3GW]," Zhang said in an interview in London. China generates only 120 megawatts of its electricity from solar power, so the goal represents a 75-fold expansion in just over a decade.

"We are now formulating a plan for development of renewable energy. We can be sure we will exceed the 15% target. We will at least reach 18%. Personally I think we could reach the target of having renewables provide 20% of total energy consumption."

That matches the European goal, and would represent a direct challenge to Europe's claims to world leadership in the field, despite China's relative poverty. Some experts have cast doubt on whether Britain will be able to reach 20%. On another front, China has the ambitious plan of installing 100m energy-efficient lightbulbs this year alone.

Beijing seeks to achieve these goals by directing a significant share of China's $590bn economic stimulus package to low-carbon investment. Of that total, more than $30bn will be spent directly on environmental projects and the reduction of greenhouse gas emissions.

But the indirect green share in the stimulus, in the form of investment in carbon-efficient transport and electricity transmission systems, would be far larger.

HSBC Global Research estimated the total green share could be over a third of the total package.

China also believes the price reforms that will take place in its economic recovery programme will lead to more efficient use of resources and an increased demand for renewable energy.

"Due to the impact of global financial crisis, people are all talking about green and sustainable development," Zhang added. "Enterprises and government at all levels are showing more enthusiasm for the development of solar for power generation, and the Chinese government is now considering rolling out more stimulus policies for the development of solar power."

He said the government would also plough money into the expansion of solar heating systems. He said the country was already a world leader, with 130m square metres of solar heating arrays already installed, and was planning to invest more. The US goal for solar heating by 2020 is 200m square metres.

Zhang was speaking in London on a day China came under increased pressure from Washington to do more cut its emissions.

David Sandalow, the US assistant secretary of energy, said the continuation of business as usual in China would result in a 2.7C (4.9F) rise in temperatures even if every other country slashed greenhouse gas emissions by 80%.

"China can and will need to do much more if the world is going to have any hope of containing climate change," said Sandalow, who is in Beijing as part of a senior negotiating team aiming to find common ground ahead of the crucial Copenhagen summit at the end of this year.

"No effective deal will be possible without the US and China, which together account for almost half of the planet's carbon emissions."

Zhang said China was pursuing "a constructive and a positive role" in negotiations aimed at agreeing a deal in Copenhagen. As part of that agreement, he said developing countries would have to pursue "a sustainable development path", and said Beijing was open to the idea of limits on the carbon intensity of its economy (the emissions per unit of output).

"We have taken note of some expert suggestions on carbon intensity with a view to have some quantified targets in this regard. We are carrying out a serious study of those suggestions," Zhang said.

Zhang told the all-party parliamentary China group in Westminster yesterday that Beijing's stimulus package was already showing signs of re-energising the Chinese economy. He said it grew by 6.1% in the first quarter of this year, and growth in the second quarter would be stronger than the first. He predicted that China would meet its target of 8% growth this year.

• This article was amended on Thursday 11 June 2009. We confused the absolute with the incremental in reporting that a rise in temperature of 2.7C corresponds to an increase of 36.9F. It is 4.9F. This has been corrected.