A Tesla Model Y owner has created what is arguably one of the most useful DIY accessories ever designed for a mainstream electric car. Using some clever DIY strategies and conventional solar panels, the Model Y owner was able to design a system that allows his all-electric crossover to charge from the sun while it’s parked outside.

In a post on the r/TeslaLounge subreddit, the Model Y owner shared that his DIY Tesla solar array charger has been under development for the past two years. Today, it is in proof of concept form, but it is already providing his vehicle with 20-60 miles of charge per day depending on its configuration. That’s a substantial amount of charge for a vehicle that’s just parked under the sun.

The Model Y owner noted that his tests with the product have been done in Los Angeles, where the sun is in abundance. Tests of the system have only been limited to five hours of charging to account for bad weather during winter. So far, the results of the tests have been encouraging, with the Model Y gaining 20 miles with the system’s 2,000 watt model through AC charging and 60 miles with the system’s 4,000 watt model through DC charging.

The Model Y owner’s current setup uses telescoping carbon fiber tubes to deploy and retract the solar panels. This allows the full setup to avoid exceeding the Model Y’s maximum roof weight capacity of 165 lbs. The solar charger is also designed to be as non-intrusive as possible, as even with its solar panels fully extended, the entire setup still fits inside one parking space.

The system’s current prototype, Beta 1, stands 11 inches tall and is made of wood and carbon fiber tubes, but a Beta 2 version made entirely of carbon fiber and measuring just 6 inches in height is in the works. The Model Y owner has a website for his project, DartSolar.com, where he posts updates on the solar charger’s development. The Model Y owner also noted that he is looking to hit a cost of about $1 per watt, which should make the expanding solar charger reasonable.

The reception to the Model Y owner’s solar charger has been quite positive, with members of the r/TeslaLounge subreddit appreciating its benefits and its rather straightforward approach to solar-powered electric vehicle charging. Other EV owners further observed that the solar array probably helps keep the cabin cool as well, further preserving the vehicle’s battery charge.