Introduction: Solar Shed - One Year Later
Nearly one year ago, I assembled and modified a 7x4 metal apex shed to accommodate a 245 watt solar panel to power tools inside the shed find out more here. During the time of using the shed, I have learnt lots about the ups and downs of solar power and small, metal sheds and here I will share them with you. If you would like to find out more information about the solar shed along with monthly updates click here!
Insulation is important - Throughout the time of the shed being sitting their, it has experienced almost every weather condition that we know of. Torrential rain, thunder storms, snow, extreme heat, powerful winds, sub zero temperatures, all of which the shed lived through yet not ideally. First of all I remember the first crisp, winter day we experienced last year, I went to the shed with layers of clothes on to go and solder a PCB. I stepped inside and bloody hell it was cold. Condensation from the previous day had frozen along the tin walls and ceiling, every tool left out on the bench was almost too cold to work with it was horrible! The other extreme happend when it was a clear, sunny, 30 degrees centigrade day when the sun stood bright in the sky. These days are great for the solar panel yet make the inside of the shed feel like an oven. Throughout the day, the small room heats up a lot with the green walls! After experiencing this for numerous times, I decided enough was enough and make the decision to install chipboard panelling along the inside of the shed as well as a polystyrene layer and then a layer of roof tiles, like those on the ceiling of recreational or meeting rooms, to retain the heat in the cold and keep the cold in int the heat. I also think it is worth mentioning my small 45watt tubular greenhouse heater that keeps the heat topped up in the cold, freezing conditions but.
Energy storage is still a headache - When I published my first instructable on the shed, I had one battery collecting electricity from the sun. This would charge reasonably quickly on a light/sunny day and if the conditions throughout the week where consistent to that of that light/sunny day, the solar panel would be generating electricity even when the battery was full meaning there was lots of wasted energy. However, when I went out at the week end or night, I would use the battery's capacity with my heater and soldering iron quickly and thus be left with no power when I need it the most. I have lowered the significance slightly by installing another battery in parallel which means it takes longer to charge and longer to discharge but not by much, which still poses a need for a better method of storing energy.
Step 1: Continued...
Water finds holes you didn't know existed - As I mentioned earlier, the shed has had to withstand heavy downpours. This meant relentless hammering of raindrops on the metal shed roof. The roof is secured to the shed with screws into roof purlins. The roof panels have to be secured firmly onto the shed which means there are lots of screw that run down, through the layers of metal into the shed. Whenever it rains, the water runs down, through these holes and drips inside the shed. I have left the shed for a week several times and come back a week or so later to find a huge puddle on the floor. I tried several methods like putting foam in the gaps, using silicon to block up the holes and even putting a plate up on the inside to prevent dripping. However, the water somehow managed to penetrate through these barriers, even after trying to work out the culprits. After the repetition of this issue, I decided that the shed needed an extra layer of roof that covered up all of the holes in the metal. I solved this problem by using plywood and felt wood tiles. I used a sheet of plywood and glued baton onto the the edge of the plywood. This sheet was then screwed into the tin roof. Next, I used black bitumen paint and then adhered the green felt roof tiles it. I could now guarantee no water would drip into the shed. Finally, I secured the solar panel back onto the shed to one side to decrease the amount of holes that would need to be drilled through and into the shed. This also meant the solar panel leads could run through the side of the shed not through the top which also gave less paths for the water.
Step 2: Other Improvements
- DC to AC inverter - Using a 1500w inverter, I am able to power low power devices for a while. This includes a 40w soldering iron, a 40w tubular heater, a desk lamp, a fan and other devices within a similar power usage (nothing outrageous like a vacuum cleaner or fan heater)
- 20A charge controller -Originally, I connected the inverter directly to the solar charge controller and tested it out. Soon after doing this the 15A charge controller flickered rapidly and was receiving no input current even when the battery was discharged on a sunny day. I bought another one, this time 20A and connected it directly to the leisure batteries under the bench. This setup works perfectly and I haven't had any issues with it so far!
- Water collection system -I also added a water collection system because when it rained the water would simply drip off the edge which didn't look great. I attached small shed guttering and ran two tubes down into a central water butt.
- Roof strengthening -To support the new roof covering and insulation, I added a steel angle at the ridge the support and insure that any extra weight could be carried. This works perfectly and now support the extra layers of solar panel, roof tiles and plywood.
Overall, the solar shed is still standing strong and hopefully will for upcoming weeks, months and even years! Minor improvements have been made to make the shed more insulated (chipboard on walls with polystyrene and fibre roof tiles), more Eco friendly (water harvesting system and new battery and all round ready for another year of making inside of it. To follow the solar shed story click me and to find great product reviews as well as projects click me.