April has been a month full of ups and downs for greentech policy so far.

In a big win for the U.S. industry, the Senate on Thursday passed a housing stimulus bill that also extends renewable-energy production tax credits for one year and investment tax credits for solar-energy and fuel-cell projects for eight years.

Two U.S. senators, Maria Cantwell, D-Wash., and John Ensign, R-Nev., introduced the proposal last week (see Solar Roundup: Another Tax-Credit Proposal).

"The Senate has recognized the urgency of taking timely action to extend these incentives," said Gregory Wetstone, senior director of government and public affairs at the American Wind Energy Association, in a written statement. "We look forward now to working with our many friends in the U.S. House of Representatives to move this bill forward…. Every day of delay tolls a greater risk on investments in new clean-energy projects and manufacturing facilities."

The Senate had previously failed to approve extensions for the credits, which are set to expire at the end of this year (see Renewable Tax Incentive Still At Risk, President Signs Energy Bill and Senate Rejects Green Incentives to Pass Energy Bill).

A group of 154 businesses and organizations delivered letters to the Senate on Tuesday claiming that a failure to extend the credits could put 116,000 jobs and $19 billion of investments at risk.

The bill also authorizes $400 million of clean-energy bonds and extends credits for energy-efficient appliances, homes and commercial buildings.

The House of Representatives still needs to approve the bill before the extensions become official. The House previously has approved bills that extended the credits, which were then rejected by the Senate.

Also in the United States, Maryland’s General Assembly passed a bill to boost its renewable portfolio standard to 20 percent by 2022. Its previous goal was to get 9.5 percent of its electricity from renewable sources by 2022. Gov. Martin O’Malley is expected to sign the bill into law before the end of May.

The state also set a goal of reducing its per-capital electricity consumption 15 percent by 2015 and created a strategic energy investment fund, funded by the state’s carbon cap-and-trade program, to increase energy efficiency, according to Renewable Energy World.

In New York City, Mayor Michael Bloomberg’s congestion-pricing plan to charge between $8 and $21 for cars entering midtown Manhattan died last week when Democrats in the State Assembly decided not to bring the plan to the Assembly floor (see Green Light post).

But the mayor is still pursuing an environmental agenda. On Tuesday, the Associated Press reported Bloomberg hopes to put 2 megawatts of solar panels on city-owned buildings in all five boroughs. The plan is not a done deal, according to Dow Jones, which reported that the city’s electric utility, Consolidated Edison, is limited to accepting 10 kilowatts of solar, which might not be enough to accept the 2-megawatt project.

In California, a group has introduced a ballot initiative that would boost the state’s renewable-energy target from 33 percent by 2020 to 40 percent by 2020 and 50 percent by 2025, according to the Los Angeles Times. But a number of environmental groups oppose the plan, which they say is riddled with loopholes, the newspaper reported (also see this post by The Wall Street Journal’s Environmental Capital blog).

The Golden State also has continued its years-long fight with the U.S. Environmental Protection Agency over whether it can restrict greenhouse-gas emissions from vehicles. Rep. Henry Waxman, chair of the House Oversight and Government Reform Committee, on Wednesday subpoenaed documents related to the EPA’s decision to deny a waiver that would have allowed the state to set its own standards (see Looking for Answers from the EPA and EPA Rejects California Vehicle-Emissions Standards).

News outside the United States also was mixed.

China last week said it would double its renewable-energy consumption from 2005 to 2010, targeting a goal of 10 percent of its energy from renewable sources.

Meanwhile, German environment minister Sigman Gabriel told Stuttgarter Nachrichten he would withdraw a proposal requiring 10 percent ethanol to be mixed into gasoline by next year, up from 5 percent today, based on reports that more than 2 million cars in Germany wouldn’t be able to run on the blend (see Green Light post).

And on Wednesday, oil giant Royal Dutch Shell said it would stop investing in Europe if the European Union forces heavy polluters to buy emissions credits at a cap-and-trade auction, according to the Times of London. The EU has been considering a proposal that would require oil companies and others to buy 20 percent of their emissions credits -- now free -- at auction starting in 2013, rising to 100 percent by 2020, the newspaper reported.