{"id":1462,"date":"2026-01-13T12:51:31","date_gmt":"2026-01-13T12:51:31","guid":{"rendered":"https:\/\/blog.hslracing.com\/myhome\/?p=1462"},"modified":"2026-01-13T13:11:40","modified_gmt":"2026-01-13T13:11:40","slug":"solar-and-storage-december-2025-energy-usage-and-ecoflow-stream","status":"publish","type":"post","link":"https:\/\/blog.hslracing.com\/myhome\/2026\/01\/solar-and-storage-december-2025-energy-usage-and-ecoflow-stream.html","title":{"rendered":"Solar and Storage \u2013 December 2025 Energy Usage and EcoFlow Stream"},"content":{"rendered":"

December 2025 updates<\/p>\n

December Electric:<\/p>\n

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I managed to maintain a 29.11% Peak\/Off-Peak ratio, which is an improvement on last month’s 32.67%.<\/p>\n

This is largely due to the purchase of some additional battery units – more on that later.<\/p>\n

Much of the month was overcast, and\/or had minimal sunshine, but an average UK December.<\/p>\n

Electricity costs for the month of December: \u00a3226.31 for 2025, \u00a3284.18 for 2024 and \u00a3536.66 for 2023 – slightly better than last year, and less than half of the year before.<\/p>\n

Electricity demand for the month of December: 1656Wh for 2025, 1751kWh for 2024 and 1815kWh for 2023.<\/p>\n

The cost for this year was around \u00a358.00 less for 96kWH less usage.<\/p>\n

The off-peak\/peak\/SC values for December were \u00a30.07\/0.26716\/0.488 for 2024 vs \u00a30.07\/\u00a30.29198\/0.4879 for 2025, peak is slightly down, but the standing charge is up.<\/p>\n

This can also be seen in the month on month usage vs cost graphs:<\/p>\n

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December Solar:<\/p>\n

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Actual production for December far exceeded the forecast for every day, often by way more than double.<\/p>\n

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The various arrays produced the following levels of energy: Garage 43.87kWh, Office 40.33kWh, East 14.74kWh, West 23.36kWh for a total of 122.30kWh which is another drop from last month<\/p>\n

A relatively poor month for solar production, I managed to export 14.52kWh for a total saving of \u00a32.18.<\/p>\n

The import costs of \u00a3226.13 less the export savings of \u00a32.18 means my net cost for December was \u00a3223.959 for 1656kWh of demand making my average rate \u00a30.1348\/kWh.<\/p>\n

December Gas:<\/p>\n

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Gas costs for the month of December: \u00a3135.61 for 2025, \u00a3198.60 for 2024 and \u00a3172.58 for 2023.<\/p>\n

Gas usage for the month of December: 2914kWh for 2025, 3116kWh for 2024 and 2538kWh for 2023.<\/p>\n

\u00a363.00 less than last year, for only slightly less gas usage.<\/p>\n

Gas prices remained about the same this month, I would have paid a lot more had I still been on the Octopus Standard Tariff, which was \u00a30.0699 per kWh for December \u00a3212.36 ((2914 * 0.0699) + 8.67sc) or an additional \u00a376.75 for the month.<\/p>\n

The heating was on for the entire month, I also include a temperature graph to show how gas usage for heating was also affected by the outside temperatures.<\/p>\n

Again all visible in the usage vs cost graphs.<\/p>\n

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There were no Saver Sessions or Free Energy Sessions this month.<\/p>\n

I made use of some Black Friday sales codes to purchase four EcoFlow Stream AC Pro<\/a> batteries.<\/p>\n

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These are intended as ‘add-on’ batteries for a balcony solar system that uses the EcoFlow Stream Ultra<\/a> that has 4 x MPPT connections each of which can have a 500W solar panel connected to it.<\/p>\n

Each one has a 1.92kWh capacity and they can be daisy-chained together to create a larger battery. You can have up to 6 EcoFlow Stream units connected within your property, I am unsure if you can potentially have more if they are not actually connected to each other, but used as independent (sets of) items.<\/p>\n

If you intend to ‘back feed’ electricity into your house, then in the UK, these must be connected via a fused spur. If however you only use them to ‘feed’ appliances that are plugged into their output ports, then you can simply plug them into a socket.<\/p>\n

I have 3 of these feeding my office network cabinet and my iMac Pro. I charge them at night on cheap off-peak electricity and they are usually exhausted by around 14:00.<\/p>\n

3 x 1.92 = 5.76kWh, however they are set to reserve the last 5% and there are a number of ’round trip’ losses which means that in reality I only get around 4.75kWh useable.<\/p>\n

The daily draw is around 13kWh, 4.75 of which is supplied by the batteries and 8.25 from ‘the grid’, the off-peak hours will be at \u00a30.07\/kWh, the peak hours may be from my other batteries or may actually be from the grid, either way, I am running around 14 of the 24 hours at the cheap rate or \u00a30.98, the remaining 10 hours are at peak rate, or from my Enphase solar\/battery installation.<\/p>\n

This means that I am saving an additional 8.5 hours at \u00a30.07 vs \u00a30.29 per kWh – \u00a30.59 (8.5 *0.07) vs \u00a32.47 (8.5 * 0.29) or an additional daily saving of \u00a31.88<\/p>\n

I was intending to put the fourth battery in the loft to feed my loft network rack, however the unit decided to ‘brick’ itself during install and I am awaiting a replacement unit.<\/p>\n","protected":false},"excerpt":{"rendered":"

December 2025 updates December Electric: I managed to maintain a 29.11% Peak\/Off-Peak ratio, which is an improvement on last month’s 32.67%. This is largely due to the purchase of some additional battery units – more on that later. Much of the month was overcast, and\/or had minimal sunshine, but an average UK December. Electricity costs…<\/p>\n","protected":false},"author":1,"featured_media":1478,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[9],"class_list":["post-1462","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorised","tag-solar"],"_links":{"self":[{"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/posts\/1462","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/comments?post=1462"}],"version-history":[{"count":4,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/posts\/1462\/revisions"}],"predecessor-version":[{"id":1482,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/posts\/1462\/revisions\/1482"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/media\/1478"}],"wp:attachment":[{"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/media?parent=1462"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/categories?post=1462"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.hslracing.com\/myhome\/wp-json\/wp\/v2\/tags?post=1462"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}