Our next question is: ‘How much power will our 12V system need to make available?’ The answer to this will determine the minimum size of the battery we need.

To work this out, we need to figure out a typical pattern of use for our various consumer units. We take as a starting point a fairly typical (summer term) week and imagine how solar power on the court could have transformed it.

On Monday, after news and a game, our group starts with our current stewardship task: cutting bramble to make space for the latest Peers’ project: Nerf Gun Shooting Range. While we cut, we listen to music on our 12V USB chargeable Bluetooth speaker, connected to a Mentor’s phone. During the morning, we’ve also been charging one of our power tool batteries, ready for Project Time. When Project Time starts, music goes off to allow full concentration. Team Shooting Range busts pallets and uses a power tool to screw the planks thus harvested into an old metal frame to create a shooting table. The speaker and the Mentor’s phone go on charge.

While Team Shooting Range builds, Team Graffiti draws plans for the art that will cover the outside walls of Steve Shelter. They turn on every LED within the Shelter so that everyone has enough light and space to work. After drawing, they turn on the computer and the mobile broadband to research non-toxic water based spray paint options and order as many colours as their budget allows. The computer and the lights stay on during lunch as a sharp shower scuppers the Peers’ picnic plans.

In the afternoon, two of the Peers run an activity for the rest of the group, which combines Taskmaster with Ready-Steady-Cook and helps us use up all the random ingredients we’ve accumulated over the past few terms. The blender is going for a good hour while the Mentors send grateful thoughts to Westmill Solar for enabling this activity to take place outside where Mother Nature will take care of the sticky splatters.  

Tuesday to Thursday is quiet: no big events, but people involved with the Eco-Park pop in and out in order to progress various projects they’ve got going on. For this period, we might factor in a little bit of phone and power tool battery charging. It’s been hot – maybe someone will remember the awesome watering system we’ve created and flicks the switch on the 12V pump sitting in the rainwater barrel, thereby effortlessly giving our veg, fruit and flowers a much-needed drink.

On Friday someone has hired the site for a teenager’s birthday party. They cook pizza in the cob oven in a leisurely fashion, turning on the 480 bulb LED fairy lights to take over from the setting sun. The blender whizzes smoothies as the cob oven starts toasting marshmallows. The teens have brought two much BIGGER speakers, which require some charging due to a bit of bad planning.

On Saturday and Sunday a group of families camps in the Orchard and uses the pizza oven again, requiring the blender and the fairy lights. The older kids set up Steve as their hang out and the LED strip lights burn until late hours. Two phones are left to charge overnight as the Court is locked.

On Sunday afternoon, the good people of OxGrow are working on the allotment and (noticing the wilting of their own crop) cross over to give the plants in the Outdoor Learning Area some water using the 12V water pump. Easy!

The above story tells what a regular, busy week in the Summer Term would look like based on current use. Next jobs are: 1) To create a table that calculates the energy consumption associated with the above pattern and 2) Factor in planned increase-of-use as the site develops.


Day 9

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