Direct solar power: Difference between revisions
(add intro) |
(add section on fridge) |
||
| Line 6: | Line 6: | ||
LOW←TECH MAGAZINE describes how the author has moved to using direct solar power for their home <ref>https://solar.lowtechmagazine.com/2023/08/direct-solar-power-off-grid-without-batteries/</ref>. Their article serves as the basis for this article. | LOW←TECH MAGAZINE describes how the author has moved to using direct solar power for their home <ref>https://solar.lowtechmagazine.com/2023/08/direct-solar-power-off-grid-without-batteries/</ref>. Their article serves as the basis for this article. | ||
== Rationale == | |||
Adapt energy consumption to the weather (as was done before the Industrial Revolution <ref>https://solar.lowtechmagazine.com/2017/09/how-to-run-the-economy-on-the-weather/</ref>). | |||
Direct solar energy is much cheaper and more sustainable. | |||
Some appliances are only used during the day. | |||
Many appliances already have batteries. | |||
== Non-electric energy storage == | |||
Two essential energy consumers raise problems in the case of direct solar power: the fridge and the cooker. These need to keep working even after the sun has set. | |||
=== The fridge === | |||
Refrigerators with the most energy-efficient labels have limited insulation, usually 2.5 cm (0.984252 inch). A thickness of about 12.5 cm (4.92126 inch), results in a reduced energy consumption drops by a factor of four. | |||
The LOW←TECH MAGAZINE article on direct solar power explains: "''Research shows that doubling the insulation thickness from 2.5 cm (standard insulation) to 5 cm reduces the annual electricity consumption of a refrigerator (50 litre capacity) from 250 to 125 kilowatt hours. 13 With an insulation thickness of 10 to 12.5 cm, electricity consumption halves again to around 60 kilowatt hours per year. Even thicker insulation brings a smaller reduction in electricity consumption and is no longer attractive because thicker insulation also increases the cost and size of the refrigerator. The study concerns a solar-powered AC fridge that operates thanks to an inverter and a battery, which is less energy-efficient than a direct solar-powered fridge.''"<ref>Gupta, B. L., Mayank Bhatnagar, and Jyotirmay Mathur. “Optimum sizing of PV panel, battery capacity and insulation thickness for a photovoltaic operated domestic refrigerator.” Sustainable Energy Technologies and Assessments 7 (2014): 55-67.</ref> | |||
A water tank inside the fridge can further increase its cooling capabilities. The water is converted to ice during the day, and this helps keep the fridge cool at night. | |||
Such a fridge would open at the top, instead of at the front. The cool air is heavier and this way of opening the fridge reduces energy consumption. | |||
The LOW←TECH MAGAZINE article mentions: "A study of direct solar refrigerators in very sunny regions (Texas and New Mexico, USA) showed that they maintained their cooling capacity for 6 or 7 days without power supply. The units operated year-round with solar panels of only 80W to 120W."<ref>Ewert, M., et al. “Photovoltaic direct drive, battery-free solar refrigerator field test results.” Proceedings of the solar conference. American solar energy society; American institute of architects, 2002.</ref> | |||
== Heating == | |||
Coming soon | |||
== Citations == | == Citations == | ||
<references /> | <references /> | ||
Revision as of 12:02, 17 September 2023
Introduction
Common solar power setups include four elements: solar panels, charge controller, inverter, and a battery pack. Out of these, the batteries are the ones that will need replacing sooner than the other components. Additionally, the more frequent replacement of the batteries also relies on fossil fuel to produce the equipment needed for the solar power setup. The batteries end up being the most costly component of the setup, and also the component with the largest fossil fuel footprint.
We can move away from using batteries though a combination of optimizing the energy consumers in our house to only consume energy during the daytime (or when the sun shines on the panels) and a shift in our mentality away from "infinitely available" energy.
LOW←TECH MAGAZINE describes how the author has moved to using direct solar power for their home [1]. Their article serves as the basis for this article.
Rationale
Adapt energy consumption to the weather (as was done before the Industrial Revolution [2]).
Direct solar energy is much cheaper and more sustainable.
Some appliances are only used during the day.
Many appliances already have batteries.
Non-electric energy storage
Two essential energy consumers raise problems in the case of direct solar power: the fridge and the cooker. These need to keep working even after the sun has set.
The fridge
Refrigerators with the most energy-efficient labels have limited insulation, usually 2.5 cm (0.984252 inch). A thickness of about 12.5 cm (4.92126 inch), results in a reduced energy consumption drops by a factor of four.
The LOW←TECH MAGAZINE article on direct solar power explains: "Research shows that doubling the insulation thickness from 2.5 cm (standard insulation) to 5 cm reduces the annual electricity consumption of a refrigerator (50 litre capacity) from 250 to 125 kilowatt hours. 13 With an insulation thickness of 10 to 12.5 cm, electricity consumption halves again to around 60 kilowatt hours per year. Even thicker insulation brings a smaller reduction in electricity consumption and is no longer attractive because thicker insulation also increases the cost and size of the refrigerator. The study concerns a solar-powered AC fridge that operates thanks to an inverter and a battery, which is less energy-efficient than a direct solar-powered fridge."[3]
A water tank inside the fridge can further increase its cooling capabilities. The water is converted to ice during the day, and this helps keep the fridge cool at night.
Such a fridge would open at the top, instead of at the front. The cool air is heavier and this way of opening the fridge reduces energy consumption.
The LOW←TECH MAGAZINE article mentions: "A study of direct solar refrigerators in very sunny regions (Texas and New Mexico, USA) showed that they maintained their cooling capacity for 6 or 7 days without power supply. The units operated year-round with solar panels of only 80W to 120W."[4]
Heating
Coming soon
Citations
- ↑ https://solar.lowtechmagazine.com/2023/08/direct-solar-power-off-grid-without-batteries/
- ↑ https://solar.lowtechmagazine.com/2017/09/how-to-run-the-economy-on-the-weather/
- ↑ Gupta, B. L., Mayank Bhatnagar, and Jyotirmay Mathur. “Optimum sizing of PV panel, battery capacity and insulation thickness for a photovoltaic operated domestic refrigerator.” Sustainable Energy Technologies and Assessments 7 (2014): 55-67.
- ↑ Ewert, M., et al. “Photovoltaic direct drive, battery-free solar refrigerator field test results.” Proceedings of the solar conference. American solar energy society; American institute of architects, 2002.