Tag Archives: solar power

An Impossible Made Possible: the Green Energy Revolution

Since the cost of renewable energy can now be competitive with fossil fuels. Government, corporate and consumer interests finally seem to be aligning.  The stock market has noticed. After years of underperformance, indexes that track clean-energy stocks bottomed out in late 2018. The S&P Global Clean Energy index, which covers 30 big utilities and green-technology stocks, is now up 37% over two years, including dividends, compared with 18% for the S&P 500.

This year’s Covid crisis will delay some renewable projects, but could speed up the energy transition in other ways. Alternative-energy spending has held up much better than spending on oil and gas. Globally, clean-energy investment is now expected to account for half of total investment in the entire energy sector this year, according to UBS.  Moreover, the crisis has pushed governments to spend money, including on renewable technologies. The massive stimulus plan announced by the European Union last month is decidedly green. The German government increased electric-car subsidies as part of its pandemic-related stimulus package rather than rolling out a 2009-style “cash-for-clunkers” program. China’s plans include clean-energy incentives, too.

Solar and wind are now mature technologies that provide predictable long-term returns. Big lithium-ion batteries, such as those that power Teslas, are industrializing rapidly. More speculatively, hydrogen is a promising green fuel for hard-to-decarbonize sectors such as long-haul transport, aviation, steel and cement.  Many big companies—the likes of Royal Dutch Shell, Air Liquide and Toyota —have green initiatives worth many hundreds of millions of dollars. They are, however, a relatively small part of these large businesses, some of whose other assets may be rendered obsolete by the energy transition… Early-stage electric-truck maker Nikola jumped on its market debut this month to a valuation at one point exceeding that of Ford.

Investors might be better off looking at the established specialists in between. Vestas is the world’s leading manufacturer of wind turbines. Orsted, another Danish company, has made the transition from oil-and-gas producer to wind-energy supplier and aspires to be the first green-energy supermajor. More speculatively, Canadian company Ballard has three decades of experience making hydrogen fuel cells.

Rochelle Toplensky, Green Energy Is Finally Going Mainstream, WSJ, June 24, 2020

Flowering the Sahara

The installation of large-scale wind and solar power generation facilities in the Sahara could cause more local rainfall, particularly in the neighboring Sahel region. This effect,  could increase coverage by vegetation, creating a positive feedback that would further increase rainfall.

Wind and solar farms offer a major pathway to clean, renewable energies. However, these farms would significantly change land surface properties, and, if sufficiently large, the farms may lead to unintended climate consequences. In this study, we used a climate model with dynamic vegetation to show that large-scale installations of wind and solar farms covering the Sahara lead to a local temperature increase and more than a twofold precipitation increase, especially in the Sahel, through increased surface friction and reduced albedo. The resulting increase in vegetation further enhances precipitation, creating a positive albedo–precipitation–vegetation feedback that contributes ~80% of the precipitation increase for wind farms…

This highlights that, in addition to avoiding anthropogenic greenhouse gas emissions from fossil fuels and the resulting warming, wind and solar energy could have other unexpected beneficial climate impacts when deployed at a large scale in the Sahara, where conditions are especially favorable for these impacts. Efforts to build such large-scale wind and solar farms for electricity generation may still face many technological (e.g., transmission, efficiency), socioeconomic (e.g., cost, politics), and environmental challenges, but this goal has become increasingly achievable and cost-effective

Exceprts from Yan Li, Climate model shows large-scale wind and solar farms in the Sahara increase rain and vegetation, Science, Sept. 7, 2018