Solar Powered Recording Studio

Sunpower Studios runs entirely on solar power.
This is generated by a 3.5 kWatt system, utilizing two Outback inverters, an Outback maximum power point tracker, and a 2500 amp-hour 48 volt battery storage system.
Theoretically, that is enough storage to run for three days without sunlight. 

Basically it works this way :

The solar panels convert sunlight to electricity, which is then stored in the battery bank.
The storage voltage is 48 volts DC, which provides superior performance to 12 or 24 volt systems. The DC voltage is then converted to standard mains 240 volt AC by the inverters. During the day, the panels supply power for studio equipment,  and for domestic needs, and  after sundown, the whole setup is run from power stored in the batteries.

Comments on Solar Panels
Solar panels are a wonderful piece of modern technology, and are basically the opposite of an LED. (Light emitting diode – the sort found on  most electronic equipment, and in a lot of torches these days). The LED converts electricity to light. Solar panels convert light to electricity.
Their simplicity and zero need of maintenance are a great feature. Occasional cleaning is necessary of course, depending on how long ago it rained! I have a friend who purchased
Some solar panels about 20 years ago when they were first available. They are still producing the same output today.
These days, the angle of the panel to the sun is not so critical as it was. The panels we use here (BP solar) show very little variation in output from 30 degrees to the normal. After that of course, it drops off until there is zero output at 90 degrees. A mechanical tracker can minimize this effect, but in our valley, there is little advantage to this. Trackers are useful if one lives on a plain. However, their added mechanical complexity and cost are not usually worthwhile.

Comments on Batteries 
This is the most maintenance the system requires. The lead-acid battery bank needs constant monitoring for water level and cleanliness. The useful life of a battery bank is somewhere around 20 years if maintained carefully. That means accurate charging, and constant monitoring. This is done electronically by the Outback gear, and is sophisticated and effective. Of course, replacing the battery bank is an expensive exercise.

Advantages
Since none of the system is connected to the mains (it is not available in Totnes Valley) the power supply is not subject to power outages, or other fluctuations occasionally seen on the power grid. This makes for a very clean and stable power supply, and we have only had one equipment failure in 10 years.(interestingly enough, a spider had made its home in the (older model) inverter and shorted out the control board. It was replaced under warranty).

However, while useful and functional, there are quite a few disadvantages to living on solar power.

Disadvantages
Unfortunately, solar panels suffer the same problem as all electronic gear – they are sensitive to heat. This means that the hotter they get, the less power they produce. The reverse is also true of course. At 25 degrees C, the panels produce 80 watts each, but at 50 degrees C, they are half that – only 40 watts. At 0 degrees C, the output could be as high as 100 watts. This “negative temperature characteristic” of solar panels is seldom advertised or known about generally.
Although there is plenty of power to run the studio and the house, there are some major
lifestyle adjustments to be made in order to live on solar power. Any appliance that converts electricity to heat, draws too much current. For instance our entire system would be needed to power most domestic electric water heaters. An electric stove uses more power than that, and a modest electric air conditioner will use all that power and more.
That is the major reason for building the studio out of straw bales. The thermal efficiency is so great that external heating and cooling of the building is not required.
Solar power is also very expensive. It would take 50 years on the average, for a grid connected urban user, to pay as much as we have to set up this system.
(Sydney University would need 400 acres of North-facing solar panels, if it was to be powered entirely from solar).
In practice, we still need to run the generator occasionally if there is a string of cloudy days, or if we work late into the night on successive days. (Musicians are prone to do that! )

Nevertheless, the lifestyle in Totnes Valley is idyllic, and the evening silence and the stars, are wonders not generally available.

If anyone wants to know more about living with solar, I love to talk about it and you are more than welcome to contact me about that.