In today’s Electrek Green Energy Brief (EGEB):

  • Charging an electric vehicle with rooftop solar in the US is cheaper than using grid power or public chargers.
  • El Salvador commissions its very first wind farm.
  • UnderstandSolar is a free service that links you to top-rated solar installers in your region for personalized solar estimates. Tesla now offers price matching, so it’s important to shop for the best quotes. Click here to learn more and get your quotes. — *ad.

Charging an EV with rooftop solar

If home rooftop solar is used to charge an electric car in the US, it costs just $415 annually, compared to $662 on grid power at home annually, and $1,058 annually with a public EV charger, according to a study conducted by consumer solar panel installation reviews website SolarReviews. The study also found that it costs up to $1,260 annually to fill a gas car’s tank.

A typical solar EV charging setup includes: rooftop solar panels, a central string inverter that combines DC output of the solar panels to AC, and a level 2 EV charger. SolarReviews estimates that five solar panels are needed to charge an EV.

According to the US Department of Transportation, the average American drives about 13,500 miles per year, or about 40 miles per day.

Here’s how it breaks down:

Type of charging Cost Notes
Public charging stations $.28 to $.69 per kWh Varies based on location and charging station owner; additional idle fees; some require monthly subscription; cost increases over time
Grid power at home $.10 to $.40 per kWh Varies based on location and time; cheapest at night; cost increases over time
Solar power at home Less than $.11 per kWh Levelized over the course of the solar panels’ lifetime; additional solar energy can be used to offset electricity bill
Source: SolarReviews

Home solar charging also contributes the least amount of carbon emissions, as electricity from the power grid still comes primarily from fossil fuels. 

In nearly every state, the long-term cost of solar roof panels is less than buying electricity from the grid, where the average kilowatt-hour cost is rising over time. The levelized cost of home solar will remain consistent, and in most cases, will be cheaper than grid power. SolarReviews estimates that charging an  EV with solar for 25 years could result in $16,250 in savings by the end of the solar panels’ production warranty.

El Salvador wind farm

Despite the challenges of devastating hurricanes, floods, and landslides in 2020, El Salvador’s very first wind farm, the Ventus Wind Project, has now come online. The 54 megawatt wind farm, which is in Metapán, in the northwest of the country, consists of 15 Vestas V136-3.6MW turbines.

Power generation developer Tracia Network Corporation, a subsidiary of Guatemalan conglomerate Grupo Centrans, commissioned the wind farm, and worked with US consultancy firm ArcVera Renewables.

The new wind farm will help reduce El Salvador’s dependence on imported fossil fuels, which accounted for 69% of its total energy supply in 2019, according to IRENA. Another 19.6% comes from bioenergy. It will also provide greater energy price stability and diversify the national power grid.

The Ventus wind farm will prevent the emission of around 200,000 tons of CO2 annually.

Photo: Electrify America

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