Micro, Macro and Me

 After 16 months, our solar plant has generated 18 000 kWh of electricity. I expect the savings to be more than €3 000 for 2022. As I'm obsessed with global heating and avoiding CO2e emissions, I'm interested in how much CO2e we have avoided. Let's dig into the numbers: According to Sungrow - 1 kg CO2e per kWh The Inverter producer (Sungrow) compares the electricity generation with coal-burning electricity. Combining 1 kg Coal gives ~3.7 kg carbon dioxide and gives up to 9 kWh. If the thermic energy is converted to electricity with 33% efficiency, one kWh will generate 1.2 kg CO2e.  That would cancel the emissions from my entire family's personal consumption, if that number would reflect our savings. But it doesn't. Averaging to the Swedish Electricity Mix ~13 g CO2e per kWh Luckily, the electricity production in Sweden is almost coal-free. Most of the electricity is generated from wind and water, and also extracted from nuclear nucular  power. What is the CO2e cos...

Under sommaren installerade vi en solcellsanläggning i samband med en totalentreprenad. Anläggningen ger effekt som planerat, men en besiktning visade allvarliga brister i installationen. Efter sex månader av animerade diskussioner fick vi firman att rätta till anmärkningarna.  Avståndet i höjdled mellan solcellerna är nu en centimeter. Jag listar de tips som jag hade haft nytta av i denna post. Offert - innan ni skriver på Viktigast av allt är att förklara för solcellsfirman att detta inte är ett hobbyprojekt utan en starkströmsanläggning som monteras på ert hem - det måste göras enligt regler och anvisningar.  Solcellsfirman bör vara medlem i branchorganisationer som t ex Svensk Solenergi . Solcellsfirman ska vara listad hos Elsäkerhetsverket för Elproduktionsanläggningar (Lågspänning). Om företaget installerar på sin egna anläggning behöver de inte vara listade men då måste de ha egenkontrollprogram. Ring Elsäkerhetsverket om du har minsta frågetecken om Solcellsfirmans beh...

As a home and solar cell owner, I've seen two stupid incentives that will encourage some to waste electricity and encourage some other to turn off their solar systems. I'm not complaining about my electricity bill, the last one happened to be very low. Why It Is Sometimes a Good Idea to Turn Off Swedish Solar Systems Some Swedish houses with solar panels have only covered a part of the roof . Some other house owners turn them off during fall , or choose to waste energy the last months of the year. Why? They fear they will produce too much electricity, and doing so can be expensive. As a residential solar power owner, it is important not to produce more electricity than you consume. If that is the case, I qualify as a microproducer , and I don't need to pay Input Fees ( Inmatningsavgifter ) to the grid owner. If I have a surplus, the grid owner may charge me, and that may cost thousands of Swedish kronor. Fortunately, it seems that not all companies do so. This could easily ...

We have had a major renovation of the roof, with an installation of a 40-panel Solar Power system. There are still some corrections to be done by the installation company later this fall. We expect to convert some 13 MWh of solar energy to electricity per year. Some of my friends have asked me if I plan to save the energy for later usage. The short answer is "no - too expensive and too little storage capacity". Generally, it is cheaper to sell electricity to the power grid and buy when needed. Let's explore what it would mean to save energy and sell when it is more expensive: Normally, the productive hours are between 10:00 and 16:00. On a particular day (2021-09-16),  the price fell to 1.35 SEK/kWh at 2 PM. If I stored 10 kWh (13.5 SEK) at that time, I would have 9 kWh in the battery, assuming 10% heat loss for the battery. Later that evening, the price increased to 1.95 SEK per kWh. When selling that energy to the grid, I would get 17.55 SEK. That would make me 4 SEK.  ...