31 votes
Accepted

Why am I offered a 5 kW inverter with a 6.6 kW solar installation?

It could be that the system will spend such little time providing above 5 kW, once shading and losses are taken into account, that it's not worth the cost of getting the next-largest inverter. ...
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20 votes

Why am I offered a 5 kW inverter with a 6.6 kW solar installation?

Standard Test Conditions vs Real life Photovoltaic panels are rated at "Standard Test Conditions" (STC): Irradiance = 1000 W/m² Cell temperature = 25°C Air Mass = 1.5 Those conditions are achieved ...
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19 votes

What alternatives to batteries exist to store solar energy at home?

Thermal storage Surprisingly to many, conversion of electrical energy from PV (photovoltaic) panels to heat energy and storage in hot water is a potentially excellent use of the energy - provided that ...
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14 votes

Which solar power technology has the highest energy return on investment (EROI aka EROEI)?

TLDR; cadmium telluride panels have the highest EROI of the mentioned PV panels (around 34.2) EROI estimates vary widely. This is because of differences in the method of calculation, scope of the ...
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14 votes

Why am I offered a 5 kW inverter with a 6.6 kW solar installation?

Solar systems are rated at peak power. It's normal for inverters to be rated less since you will very rarely have ideal conditions to reach peak power. For example, my inverter is rated at 80% of peak ...
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12 votes

Is creating hydrogen fuel for the fuel cell from the solar panel worth considering?

Yes, if you want electricity, it's much cheaper and more efficient to just use the electricity directly from a solar panel, than to do any transformation of that electricity into any other form, then ...
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9 votes

How worthwhile is it to use energy during daylight to take advantage of grid-based solar power?

In the purist sense of "the electricity I use was actually generated by a wind farm", your idea is broadly correct. However, unless you actually have solar panels or a wind turbine on your house, that'...
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  • 3,755
9 votes

Which battery is best for solar power?

There is no "best battery." There are different kinds of batteries for different applications. Here are some things to consider, What voltage do I want? (Most DIY projects pick 12V because they want ...
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9 votes

Why is solar energy so expensive?

It is not, necessarily The initial capital cost of a plant is not the same thing as its lifecycle costs. The best way to analyze the cost impact of an energy source is to look at the total expected ...
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  • 1,027
9 votes

Why am I offered a 5 kW inverter with a 6.6 kW solar installation?

There already are some answers addressing the fact that you probably will not reach or will rarely reach the rated power of your panels. That explains why you don't need a higher rated inverter. Now, ...
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  • 191
8 votes

How worthwhile is it to use energy during daylight to take advantage of grid-based solar power?

You're being quite specific with regard to solar... but in principle, it is possible to move your electricity consumption to minimise its carbon footprint. Ecotricity (a UK "green" energy supplier) ...
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  • 3,621
8 votes
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How do white roofs cause global warming?

This counter-intuitive advice is actually the result of research. Unfortunately journalists are rarely qualified to cover any sort of science news, and this was no exception. I'll try to explain the ...
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  • 515
8 votes

What alternatives to batteries exist to store solar energy at home?

Ok, let's break this down. I will assume photovoltaic solar panels (as the question implies alternatives to batteries) and therefore skip all kinds of solar thermal collectors. Starting from electric ...
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  • 476
8 votes
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What is the amount of silicon in a 1kw panel?

Fthenakis has published more on the subject than anyone, to my knowledge. His LCA lists a whole bunch of factors, but it's roughly 1.5kg of silicon in the PV itself. But a module also has 16.1kg of ...
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8 votes

How does the solar industry fund itself?

Your first sentence is incorrect, as per the very chat discussion you've referenced: the sales price for panels is more than the cost of the panel's components. The second sentence is also incorrect: ...
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8 votes
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Can 140 square miles of solar panels power the US?

Summary No, that's way too little. I think "140 miles square" has got mangled into "140 square miles". Running the numbers Following on from one of Elon Musk's presentations, which ...
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7 votes
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Investing in Solar Panels in the UK

The Energy Saving Trust (EST) is an organisation that has no vested interest in selling you things (although their mission is certainly to encourage takeup of renewables). They have a lot of good ...
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7 votes

Investing in Solar Panels in the UK

I was quite surprised by the number of upvotes the question got, and as I've now gone ahead and had the panels installed, I'll add a few more details of what I did, in case it is of use to anyone ...
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  • 363
7 votes
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Can we build a very effective cooling system for house or apartment using solar or wind power?

A common thing to do is use the cooler temperature of the ground to reduce the temperature of your home. If building a new home, you can simply build it into a hillside or completely underground. For ...
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  • 246
7 votes

What is the difference between "hydro" and "tidal/wave"? And what is the difference between "solar (heat)" and "solar panels"?

Beware that chart - it is from 2004, and hence is very out of date! In particular, photovoltaics ("solar panels") have become cheaper much faster than anybody expected a decade ago, and wave and tidal ...
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7 votes

How can I cheaply evaluate how much solar energy I can collect?

A simple short term test like the one you are thinking about will reveal little information. Many factors affect the output of photovoltaic cells. Results from a cloudy day will differ those for a ...
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  • 3,207
7 votes

How much irradiation from the sun is required to generate solar power?

Solar Irradiance The amount of energy striking the earth from the sun is about 1,370W/m2 (watts per square meter), as measured at the top of the atmosphere. This is the solar irradiance. The value at ...
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7 votes
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Are there solar panels that can survive extreme temperature changes?

Effects of extreme temps on solar panels This answer on Chemistry.SE lists the three major factors which lead to solar cell degradation: Temperature UV exposure Mechanical damage ...
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6 votes
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Is the energy used to manufacture and install solar panels in proper balance with the energy output from them?

I asked my late father (an electrical engineer) this very question years ago and he said that essentially, the entire cost of a solar panel is the cost of the energy to make it. You dig dirt out of ...
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  • 1,807
6 votes
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Can solar energy be too focused onto a solar cell?

Yes, if the photovoltaics aren't designed for operating as concentrated PV, it can shorten the life of the cell: the additional thermal stress can be huge; the cell will operate at a higher ...
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6 votes
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Solar PV panels - Worth the cost of more efficient panels?

Rooftops are pretty much the only place where efficiency matters for PV panels, because surface area is typically a constraint there, but almost nowhere else. And the structure of UK feed-in tariffs ...
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6 votes

What alternatives to batteries exist to store solar energy at home?

"Solar panel" includes both thermal panels and photovoltaic panels. A common way to store and use heat is in a domestic hot water storage tank. This is generally cheaper and more efficient than PV ...
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6 votes
Accepted

Determine the solar installation size based on W/m² solar irradiance data

The conversion of light into electricity happens pretty much instantaneously. Well, it takes time, but such a short amount of time that we can't perceive it without some serious instrumentation. So ...
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6 votes

Converting from W/m² to kWh/m²/day

If your data is minute-by-minute then that's exactly what you need to do. Adding all the minute-by-minute W/m² figures for a day (you should have 1440 of them, so use a spreadsheet or script) will ...
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  • 2,037
6 votes
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Is a solar cell phone charger a sustainable choice?

The best article I could find which addresses this question is "Life‐Cycle Assessment of Solar Charger with Integrated Organic Photovoltaics". Their conclusion: Because of the complicated ...
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