At the Pathways to 100% Renewable Energy conference in San Francisco, recently, the major question was not whether or not there can be 100% renewable energy sources, but how to get to 100% renewable energy sources. There were several themes that carried throughout the conference.

Our thinking is out of date That’s because it’s hard for us to see beyond our mental map and cultural filters. Instead of talking about scarcity and limits to growth, which are part of this mental map, she believes that to find solutions we need to reframe the issue.

Predictions underestimate the growth of renewables Keynote speaker Eric Martinot, after providing many examples of fast growth in renewables, noted that we’re already exceeding conservative scenarios. Projections from the World Bank and others have generally been a decade off or a factor of 10 lower than actual outcomes. That’s right: we’re heading down the path to 100% renewables more quickly than predicted.

Some areas have already reached 100%. Case in point: Rhein-Hunsrueck, Germany. Starting with energy efficiency and moving on to generating its own power, the region of 101,000 inhabitants now produces not 100% but 104% of its energy from renewable sources.

Technology is not a barrier A study of conditions in 2005 and 2006 showed that in that period, California could have met its electricity needs for 99.8% of all hours from solar and wind — without using demand-response, much storage, or oversizing. In Mexico, a combination of wind and solar can greatly reduce intermittency problems, with hydro or geothermal easily making up the remainder of electricity needs. Those who doubt these assessments need look no farther than the increasing number of areas that have already reached 100% or are close to doing so.

As more regions move to renewables, more people will see the value of making the switch. That increased public awareness and acceptance will help overcome the real challenges, which are social and political.

Renewables make financial sense The biggest cost of renewables is in the up-front investment; once they’re in place, they don’t need to be supported by infrastructure like pipelines. Many can be sited locally, reducing the need for costly transmission lines.

Investors are catching on. For example, they’re beginning to understand solar as an asset class and are realizing it’s a great bet: It’s a proven technology, it harnesses an unlimited source of power, and the default rate on solar projects hovers around zero. Solar provides a hedge against volatile future power costs.

Investments in renewables are expected to double by 2020 or 2030. Given the way renewables tend to outperform predictions, perhaps we’ll see that even sooner.

These themes point out that while we are trying to figure out a way to reach 100% implementation of renewable energy sources, they are already moving in that direction. If we were to trust in the renewable technologies and implement them in larger numbers, the benefits of renewable energy sources might be more noticeable and help propel a wider adoption of these technologies.

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