Panel Angles - winter and rest of year

Now that we've experienced Winter, how has our house performed? What have we learned?

Earth

E - Challenge Assumptions
I assumed pointing a solar panel directly at the sun was the best. Wrong! Indirect sunlight is substantial, so the flatter the angle, the more indirect sun you get. In May, June and July the sun gets no higher than 33 degrees above the horizon here, but the best angle for the solar panels is 5 degrees higher, not lower! Nature has a way of being more complex than we expect. However, our 50 degree panels performed 29% better than our 8 degree panels theoretically, but we quickly lose that performance advantage unless we raise the panels back up as high as possible for the other 9 months.

Lesson: challenge consultants to collaborate for better solutions.

Air

A - Count the Cost
We questioned whether our solar power could generate enough to run both the house and the car over winter. Luckily, with only 2 days of no sun, only a small amount of power was needed from the grid. After checking main energy uses - heating, cooking, laundry and car charging, we changed habits to reduce reliance on the power grid for peak demand by being more mindful about timing our activities. The biggest saving by far is our EV that runs on sun with zero carbon emissions. We're stoked that over 50% of energy generated in winter (our handprint) went towards recovering the embodied energy cost of the car, house... and the driveway that cost more than the solar system!

Lesson: measure to prove the need for change.

[Postscript Sept 2021: Tanglewood lifetime generation is NET150 i.e generated 150% more than used, leaving more water in the hydroelectric dams and more coal in the ground, to the benefit of everyone... and the climate.]

Water

W - Accept the Cold Hard Facts

Small but significant steps enabled us to keep warm this winter with the heater on for only 2 hours over the entire season. Careful to keep humidity as low as possible, we diligently opened small north-facing windows during the day and turned off the kettle as soon as it reached boiling point. We have a powerful but quiet kitchen extractor fan, and the bathroom has a Lunos vent with a heat exchanger that captures the warmth from the outgoing air (and steam) and transfers it to incoming fresh air. The biggest benefit comes from the ShowerDome that keeps the steam inside the shower where it condenses and runs down the drain instead of steaming up the bathroom.

Lesson: shutting out the cold takes more than just turning up the heat and closing the windows (or building a wall).

Fire

F - Celebrate Success
We had a bottle of Prosecco we wanted to open, but needed an excuse. Realising how many successes we've had, we toasted & applied our 'gratitude ritual'. We reminded ourselves that throughout winter, we returned from our chilly walks to be greeted by warmth, peace and stunning views of Mother Nature at work. We will be forever grateful for what the LBC project challenged us to do and achieve.  Our goal is to continue and leverage that challenge for the bigger differences that MUST be made NOW, locally and globally.

Lesson: rituals help us remember, rekindle and rejoice.

Consider...

Until we remember the lessons in this video, we and generations to come will suffer from the chaos of mindless, egotistical, greedy, colonial acts of many leaders today. Mac Macartney shares lessons that may help us remember. Take a deep breath, relax and sit  with Mac for 2 minutes, or watch his Children's Fire TED talk to understand why our world is in so much pain.  We look forward to meeting Mac and learning from each other next year when we visit the Eden Project, Cornwall, UK.

 

Tanglewood Solar Case Study from Equinox Design.

From Footprint to Handprint More about our solar panels and energy use.

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