One MegaWattHour of Battery Power!


Large box attached to the wall. A white metal case with blue polka dots covers it. There is a small black and white screen in the middle.

Less than a year ago, in August 2023, we installed a 4.8kWh Solar Battery at a cost of £2,900. Whenever I talk about the upfront capital costs of solar power, people rightly want to know what the payback period is. Well, after less than 10 months, the battery has given us 1MWh. To put that […]

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Fifteen MegaWatt Hours from Sunshine - Four Years with Solar Panels in London


Chart 4: Mean domestic electricity consumption (kWh per meter) by country/region. Varies between 2,973 and 3,870kWh.

Just as the UK was entering the first COVID19 lockdown, we got solar panels installed on our roof. Four years later and our generation meter shows they have produced 15,480kWh of electricity. That's a rather impressive 3,870kWh per year. This is what the average UK household uses in electricity: Our roof is non-optimal. We have […]

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We pay 12p / kWh for electricity - thanks to a smart tariff and battery


Screenshot of our electricity bill showing 320kWh consumption.

I love my solar panels. But the solar panels don't love the British midwinter. Most of the year, my panels produce more electricity than I can use. But in winter we're lucky if they produce 3kWh per day - and most of the time it is considerably less. So our winter electricity bills must be […]

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Electricity That's Too Cheap To Meter


Graph of electricity prices. Some are negative.

Nuclear power was sold to the world as a safe, clean, and economically viable source of electricity. We were told that it would be "too cheap to meter"1. Even the most ardent proponent of nuclear power will have to admit that hasn't come to pass. Construction costs for nuclear power stations are dwarfed only by […]

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eInk Display for Octopus's Agile Energy Tariff


An eInk screen with a line graph on it. The graph shows the current price of power. The eInk is mounted in a wooden frame.

I'm a little bit obsessed with building eInk displays. They're pretty cheap second hand. They're low energy, passive displays, with good-enough performance for occasional updates. Here's a new one which shows me what the current cost of my electricity is: Background After installing solar panels, a smart electricity meter, and a solar battery - the […]

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One month with a solar battery - real statistics


Graph with multiple lines. There's a spike about 6AM which is probably a kettle being boiled. Another near lunchtime which might be a microwave. The evening has a couple of hours of high use - which is probably a washing machine.

August is meant to be full of gloriously hot days. An endless parade of sunshine and drinks in the park. This year it seemed mostly grey, miserable, and prone to pissing it down at a moment's notice. We all know that solar panels' efficiency wilts in the heat, but do they get a tan work […]

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Using *over* 100% of our solar battery capacity in one day!


Line graph showing the battery's state of charge.

Please imagine I have an extreme-YouTube-shocked-face as this post's thumbnail image. We recently got a 4.8kWh solar battery installed. Batteries are still somewhat complex beasties. In order to prevent damage to the internal structure, a BMS (Battery Management System) ensures that each cell in the battery gets a fair share of wear and tear. One […]

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Solar Battery Statistics - Day One


A complex graph with multiple overlapping coloured lines.

We recently upgraded our home solar storage to 4.8kWh. The battery has sensors to detect how much solar power we're generating, and how much electricity we're buying from (or selling to) the grid. That means... GRAPHS AND STATISTICS! Our battery was commissioned just after midday. This graph shows: 1630 - it was fully charged. 2000 […]

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Review: Moixa 4.8kWh Solar Battery


Large box attached to the wall. A white metal case with blue polka dots covers it. There is a small black and white screen in the middle.

I have upgradeitis. If something newer and shinier comes out, my stupid monkey-brain compels me to buy it. Seven years ago, we installed a solar battery. It was part of an experimental project which looked at creating a community power-grid, so it came at a subsidised price. As I explained to BBC Click, the 2kWh […]

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3 years of domestic solar stats in the UK


Solar panels on our roof.

After 3 full years of having solar panels on our London roof, they've generated 11,950kWh of electricity. Nice! Here's how those three years look, according to our smart meter. kWh Solar Generation 11,950 Solar Export 7,346 Grid Import 7,521 Quick maths! The difference between the generation and the export is our solar consumption: 4,604kWh over […]

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