“Like the crack of the whip, I snap attack
Front to back in this thing called rap”
Oh, hey…forgot myself. 25 years ago, this would have sent me to the dance floor to show off my mad “running man” skills, but this is a whole other kind of power, the power of the sun!
When I started the garden years ago, I promised that I wouldn’t add to my utility usage by keeping a garden, which meant no additional water usage and no additional electrical charges. It is a covenant with the earth to not waste her resources and to use what is given to fulfill our needs. We are keeping that promise even as we add the greenhouse that will need supplemental light, heat and circulation by powering the greenhouse with solar energy!
Admittedly, both Will and I are solar neophytes. I understand the concept of harnessing the energy for use, but beyond a solar calculator or solar garden lights, we were clueless. Luckily, we are willing to try and make mistakes in order to learn about this concept as we want to employ solar for future projects (chicken coop, solar backup, solar augmentation) and we will want to do at least some of that work ourselves.
Earlier this winter I had a few coupons from Harbor Freight Tools, a discount tool company that happens to have a hobby solar kit. We thought this would be the best entry point into the world of solar energy. I purchased their 45watt solar kit along with a 12volt deep cycle battery and a power inverter. All together, these pieces will allow me to bring alternating current into the greenhouse for use for seedling heating mats, supplemental lighting if needed and much needed air circulation. Further on down the road, we can choose to link multiple kits to achieve some level of solar backup for emergencies should we need it.
Given we had such a warm weekend (IN FEBRUARY!!!!) we decided to get the kit assembled and up on the roof to be ready for seedling planting in a couple of weeks. We assembled the frame on the ground and then Will went up to the roof, while I, at first, assisted from the ground and then the roof to aid in securing the structure.
After some horsing around and a costume change, he got to work adding the panels to the frame. Adding the solar panels was relatively quick and easy, they are secured to the PVC frame with screws and nuts. Will did suggest after we completed this project that it might have been easier to assemble the entire kit on the ground and then take it to the roof as a whole…live it, learn it!
Once assembled, we felt the plastic strapping we employed to secure the frame to the roof was not going to work, it continually worked itself away from the screws, so we swapped it out with copper strapping. It is secure, and will weather nicely.
Positioning the panels to get maximum sun is also important. The entire backside of our house points due south so it is the optimum place to put panels. The kit provides two positions for placement (one winter, the other summer). However, we will watch our consumption and fill rate at the angle we have it placed to determine if we can or should shorten the angle poles to make it more flat against the roof. If you are using a kit, the choices are made for you. However, if you go the route of adding panels in a different configuration or not using a kit, you have to determine the angle of the mounting in order to capture the sunlight effectively. Here is an easy calculation to use.
Take your latitude (it is easy to get from google earth) and add 15 degrees for the winter, or subtract 15 degrees for the summer.
For example: if your latitude is 40 degrees, the angle you want to tilt your panels in the winter is: 40 + 15 = 55 degrees.
In the summer, it would be: 40 – 15 = 25 degrees.
Once the kit was secure, we ran the cables down the house (I will secure them with mounting brackets this week to the charge controller, battery and inverter. We needed something to house these items that would be weather safe and not in the greenhouse (I think the additional moisture would harm the battery and connectors), I purchased a garden storage box that fit perfectly between our air conditioner and the greenhouse and had plenty of room to hold the equipment. We drilled a hole to feed the extension cord that will bridge from the inverter into the greenhouse and to any power strip we add. Will fed the single cable (the three panels are wired to a connector that goes down to one cable) through the hinge opening at the back of the box, he then connected the battery to the charge controller and finally the charge controller to the solar panels.
We will add the inverter this week along with the extension cord and power strip, but we wanted to test the system so we connected a light on a 12v amp plug to the charge controller and it lit up beautifully. We will give the system a couple of days to completely charge the battery before use and then we will test how long it takes to fully discharge the battery under normal use.
This is an exciting first foray into solar energy and we couldn’t be more pleased with the ease of assemble and the effectiveness of the system. It is a brave new world!!!