California is taking a big jump forward in its commitment to become a truly green state by becoming the first in the US to require that all new-build homes include solar panels. The Energy Commission for the state will be taking a vote on ambitious new energy standards which would mandate solar panel inclusion on virtually every new home built from 2020.

Around 20pc of houses are now built with the capacity automatically added in, but the state is keen to make a 'quantum leap' in its standards of green energy. No other state in the US has taken such an ambitious step to mandate green energy technology for new buildings. The new rule would automatically apply to any home of three storeys and above.

The new guidelines would also promote greater use of battery storage and more use of electricity rather than natural gas. The new ruling supports California's original goal to ensure that all new buildings would deliver net zero energy within two years for domestic buildings and by 2030 for new commercial buildings. This means that all buildings can generate their own solar energy to offset the amount of fossil fuels that they need to use.

The new standard is expected to add around $30k to the cost of building a new building, but modern solar systems can last for 25 years, which means that their operating cost savings could exceed $60,000 for homeowners.

The news has been welcomed by a number of green groups and environmental campaigners. Already, the Golden State has a great renewable record, and on its sunniest days the price of electricity can actually become negative because the solar energy supply is so high. It certainly looks ready to hit new renewable heights in 2019.