Solar panel to charge hybrid?
Discussion
Up to now, roof solar panels have just been to keep the 12v battery topped up (spoiler panel on a Nissan Leaf), or run the air con when you're away from the car (the whole roof on a Fisker Karma). The new plug in Prius has a solar roof as an option to charge the car, and on a really bright day with clean panels and the car in direct sunlight all day, it might add a couple of miles to your range https://electrek.co/2016/06/20/toyota-prius-plug-p...
But when was the last dawn to dusk bright sunny day here with your car in direct sunlight all the time? And really how accurate are manufacturer range figures for any kind of car compared to everyday driving? And to get that slight bonus of a few miles, it takes a panel the size of a car roof.
But when was the last dawn to dusk bright sunny day here with your car in direct sunlight all the time? And really how accurate are manufacturer range figures for any kind of car compared to everyday driving? And to get that slight bonus of a few miles, it takes a panel the size of a car roof.
A typical EV has around 20kWhr of energy storage capability in its battery. (and getting bigger all the time) That means you'd need to feed it with a power of 20kW for a full hour to charge it (ignoring charging losses etc) from completely flat.
in the UK, with a clean solar panel, angled perfectly towards the sun, on a cloudless sunny day there is a solar insolation of around 1 to 1.2kW per square meter of solar panel. However, solar panels are at best, around 30% efficient (most panels are actually a lot worse, <20% often). So for each square meter of panel, on the best day, you'd get 300 watts power output.
Divide 20 by 0.3, and a square meter panel will therefore take 66 hours to charge your car from flat. And on a more typical overcast day, you can double that again!
Ok, so lets take a more typical half charged EV, that needs just 10kWHr of electricity, and say we get 6 hours of significant sunlight a day, you'd need a miniumum of 11 square meters (perfect sunny day) to 26 square meters (cloudy day) to harvest that energy requirement!
The biggest issue is that it's sunny during the day, when you're EV is probably parked at work.
Solutions to this issue include Work places installing solar systems (Prodrive, the famous motorsport company has just done this on their new HQ in Banbury btw, so it might become more common) or install some sort of energy storage at home, like a s/h EV battery, which is charged during the day, and then empties itself into your car (and house) in the evening/overnight.
in the UK, with a clean solar panel, angled perfectly towards the sun, on a cloudless sunny day there is a solar insolation of around 1 to 1.2kW per square meter of solar panel. However, solar panels are at best, around 30% efficient (most panels are actually a lot worse, <20% often). So for each square meter of panel, on the best day, you'd get 300 watts power output.
Divide 20 by 0.3, and a square meter panel will therefore take 66 hours to charge your car from flat. And on a more typical overcast day, you can double that again!
Ok, so lets take a more typical half charged EV, that needs just 10kWHr of electricity, and say we get 6 hours of significant sunlight a day, you'd need a miniumum of 11 square meters (perfect sunny day) to 26 square meters (cloudy day) to harvest that energy requirement!
The biggest issue is that it's sunny during the day, when you're EV is probably parked at work.
Solutions to this issue include Work places installing solar systems (Prodrive, the famous motorsport company has just done this on their new HQ in Banbury btw, so it might become more common) or install some sort of energy storage at home, like a s/h EV battery, which is charged during the day, and then empties itself into your car (and house) in the evening/overnight.
Max_Torque said:
...
Solutions to this issue include Work places installing solar systems (Prodrive, the famous motorsport company has just done this on their new HQ in Banbury btw, so it might become more common)
...
Unfortunately HMRC are advising that:Solutions to this issue include Work places installing solar systems (Prodrive, the famous motorsport company has just done this on their new HQ in Banbury btw, so it might become more common)
...
"If an employer provides electricity to an employee to charge their own
car, a benefit in kind arises representing the cost of the electricity used,
which must be reported to HMRC. "
Which I think could put off employers due to paye admin, unless they only have company car drivers.
c1derman said:
Max_Torque said:
...
Solutions to this issue include Work places installing solar systems (Prodrive, the famous motorsport company has just done this on their new HQ in Banbury btw, so it might become more common)
...
Unfortunately HMRC are advising that:Solutions to this issue include Work places installing solar systems (Prodrive, the famous motorsport company has just done this on their new HQ in Banbury btw, so it might become more common)
...
"If an employer provides electricity to an employee to charge their own
car, a benefit in kind arises representing the cost of the electricity used,
which must be reported to HMRC. "
Which I think could put off employers due to paye admin, unless they only have company car drivers.
Gassing Station | EV and Alternative Fuels | Top of Page | What's New | My Stuff