Renewable energy has always played a minor role in the US.
Despite the film industry often portraying California as being awash with wind turbines, the reality is that wind only accounts for just under 10% of energy production in the country.
Even so, there are signs that renewables are beginning to gain greater traction in the US - and elsewhere in the world - as the overall drive for sustainability takes hold.
Indeed, renewables are forecast to account for around 25% of the US energy generation mix by 2050.
At a global level renewables have a stronger foothold, at around 26% of total electricity generation, and there are predictions that this will rise to nearly 50% by 2050.
On top of this since 2019 we have seen ten US states, more than 100 cities, and a number of major US corporations committing to renewable energy targets.
In a country where fossil fuels currently produce around 80% of its energy, it is clear that the tide is beginning to turn.
The great energy rotation?
There is little doubt that non-hydro renewable energy, led by solar and wind power, are on a solid growth trajectory.
Nevertheless, it is a slow-moving trend that will be played out over several decades rather than in a few years, particularly because the shale gas revolution prompted a new generation of natural gas power plants to come online.
Current forecasts suggest renewable energy will account for around 25% of the US energy generation mix by 2050, up from just under a tenth today.
Helping to drive forward the case for renewables is the fact that in many regions wind power is now the cheapest form of energy generation.
Analysis by the US Department of Energy at the end of 2019 found that wind farms are cheaper to build and operate than gas-fired power plants.
The cost of wind power in the US had in fact increased steadily up until 2009, when power purchase agreements for wind-generated electricity peaked at about $70 per megawatt-hour.
Prices have declined steadily since then, with the national average falling below $20 per megawatt-hour for the first time.
In Europe, renewable energy gained a larger foothold much sooner than in the US. The share of renewables in gross final energy use in the European Union (EU) has doubled since 2005, according to data from the European Environment Agency.
By 2018, renewables accounted for 18% of all energy use in the EU, and 30.7% of electricity consumption.
Given the renewable energy market's potential for growth, there is little doubt that it can be an attractive investment opportunity.
The objective of the Rathbone Global Sustainability fund is to create long-term value for investors, society and the environment through companies that display strong environmental, social and governance (ESG) principles and follow a sustainability theme.
The companies that I select for the portfolio are therefore high-quality, cash-generative businesses with strong franchises, have no financial stress and are long-term thinkers.