Questions tagged [photovoltaics]

Solar panels that convert light directly to electricity. For questions on using sunlight to to heat water use [solar-thermal]

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31
votes
3answers
2k views

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

Which solar-electric technology had the highest EROEI? Energy Returned On (Energy) Invested, also known as EROI and as EROEI, has become something of a fashionable metric *but see footnote. It is ...
30
votes
5answers
1k views

Estimating the cost of solar panels and return time?

I'm interested in installing a solar array on my property, and am trying to find tools that can help me do a cost analysis so I can optimize my budget and see how long it will take to balance the ...
18
votes
7answers
5k views

What advantages (any?) has water heating via photovoltaic system over solar thermal system?

Both solar thermal water heating systems and photovoltaic systems already have a good commercial background. Efficiency of energy gain of a solar thermal system is about 80%, while photovoltaics is up ...
16
votes
3answers
6k views

Would monocrystalline or polycrystalline solar panels perform best in a UK climate?

If I were to get solar panels installed on the roof of my home, in the UK, what type should I choose? There appear to be three main types, and at present the choice appears to be between the ...
14
votes
1answer
349 views

What type of photovoltaic cells are the most environmentally friendly?

Some solar panels use silicon crystals that required careful purification and enormous quantities of energy. Some types use cadmium, which is highly toxic. Several types are noted by Wikipedia. If we ...
12
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2answers
320 views

How do I keep my solar panels clean?

What sort of cleaning regime should I have for a solar energy system, and do PV and solar-thermal panels need to be treated differently?
11
votes
2answers
570 views

Are tracking mounts cost-effective for home photovoltaic systems?

Solar PV panels are clearly more efficient at converting sunlight to electricity if they are mounted on racks that rotate to track the sun's apparent travel across the sky. However, tracking mounts ...
9
votes
2answers
139 views

How can electricity grids successfully incorporate high (50%+) penetrations of PV and wind?

Although most of the renewable energy currently consumed by the world can be turned on and off at will pretty easily (hydro and biomass), there are two potentially huge supplies, wind and PV, that are ...
9
votes
3answers
192 views

Solar PV panels - Worth the cost of more efficient panels?

We're investigating fitting solar PV to our large guesthouse in the UK. We can fit around a dozen panels on the south-facing roof (sadly this is one of the smaller roofs). Some installers are ...
9
votes
1answer
162 views

What causes photovoltaic (solar) cells to degrade?

Photovoltaic panels can have 20 or 25 year underwritten warranties with a guaranteed remaining efficiency of 80 % of the new panel. That means, that photovoltaic panels seem to degrade somehow. Why ...
8
votes
2answers
74 views

Feeding hotwater into modern appliances

Most appliances, such as washing machines and dishwashers typically take cold water and heat it internally. This is probably the most efficient way on a grid connected house with electric water ...
8
votes
2answers
242 views

What have been the economic factors behind the build of tracking PV systems?

I see there's now over 1GW of installed PV capacity in tracking systems. What have been the economic factors behind this? I'd pretty much written off both 1-axis and 2-axis tracking in my mind, ...
7
votes
3answers
13k views

How can I monitor a PV system's performance?

What are things I should monitor to track a photovoltaic system's performance? I'm not looking for a recommendation for a particular piece of kit, because such a recommendation could quickly go out ...
7
votes
1answer
276 views

Transmit solar over multiple time-zones?

I heard that at big voltages (10 000+V) the energy loss along a wire is very small. Unfortunately I've got little electrical knowledge, but this sparked up a question: Considering that peak ...
7
votes
2answers
971 views

Can I connect an inverter directly after an MPPT controller, with no battery?

Is it possible to connect a 12VDC to 220VAC inverter to the output of an MPPT solar charge controller, with no battery? This will be cheaper than having a full solar inverter, which can be really ...
7
votes
1answer
101 views

Can solar energy be too focused onto a solar cell?

I want to focus solar energy on a solar cell with the use of mirrors (that I already have) and maybe some aluminum foil. Should I not go overboard on the focusing? How can I detect if the focused ...
7
votes
1answer
95 views

What scope is there for price reductions in photovoltaic inverter costs?

In almost all of the world (except the USA, which has specific local cost challenges), system photovoltaic (PV) costs have come down a lot, to about €2 per installed watt. A large part of the ...
6
votes
3answers
171 views

How to consume all my photovoltaic electricity locally?

In a location where feed-in to the grid is not rewarded, it makes sense to somehow consume all the "oversupply" electricity from photovoltaics by yourself. How can I implement this in an automated ...
5
votes
2answers
587 views

Converting from W/m² to kWh/m²/day

I have access to live solar irradiance data (in W/m²) at each minute of the day in my location, they come in 3 types: minimum, maximum and average. How do I make use of these datas to convert to kWh/m²...
5
votes
1answer
610 views

Does a building need an equator-facing roof to take advantage of Solar PV systems?

Does a building need an equator-facing roof to take advantage of Solar PV systems? That is, in the Northern hemisphere, do I need a south-facing roof? And, conversely, in the Southern hemisphere, do I ...
5
votes
1answer
123 views

Central or Micro inverter

I want to install some solar panels around 1 kWp. All the suppliers nearby offers me a central inverter solution. Should I look for a micro inverter solution? Or is something that I shouldn't bother?
5
votes
2answers
98 views

Are green roofs more sustainable than roofs with photo voltaic?

Both types of roofs have advantages. Green roofs do not produce energy (in some cases just fruits) but they do not consume that much energy for production of panels, installation and control and do ...
5
votes
2answers
74 views

What exactly is Potential Induced Degradation in PV panels?

Can someone explain Potential Induced Degradation? I've been looking over the internet but a lot of the explanations go into too much detail.
4
votes
2answers
750 views

How much energy costs do portable solar panels save in a house?

Our Houston area HOA does not allow roof top solar panels and I doubt they would survive our hurricanes too. I discovered NRG Energy sells these portable solar panels under their goal zero brand. If ...
4
votes
2answers
1k views

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

Interested to know how to calculate how much energy photovoltaic (PV) panels would produce given x amount of solar irradiation per day - amount of direct sunlight and how much that might be effected ...
4
votes
1answer
169 views

What is the energy payback time of portable solar panels, in hours?

I'm interested in knowing the typical energy pay-back time of a solar photovoltaic panel, in terms of hours operating under an ideal scenario. Energy pay-back time (EPBT) is usually quoted in terms ...
4
votes
1answer
73 views

Solar Panel short section of string due to obstacle

Recently I have installed a set of 10 panels connected in series with 1 single Inverter. I have realised that for the first 2 hours 2 PVs have a cast shadow on them from a neighbourhood tank (that ...
4
votes
1answer
121 views

Apply solar energy solutions at our apartment?

I know this will probably get closed, but it seems that I can't find anything that will guide me in the right direction. We live in a South American country, so we have tons on sun. We also have a ...
3
votes
2answers
132 views

Photo voltaic windows Pro - Cons. Where to get them?

I intend to build a house in the near future and I want it done in a proper way. From my perspective "proper way" means also as much as self sustainable as possible. Hence I intend to generate/produce ...
3
votes
1answer
64 views

Solar charging an e-bike's lithium battery while riding

I would like to know what parts I would need to charge a 36V lithium battery for an ebike? I want to charge the battery while riding the bike for greater range.
3
votes
1answer
86 views

Which measure of solar irradiance is needed to calculate the energy output of PV systems?

According to "E = A * r * H * PR" global formula to estimate energy generated, the solar irradiance value is needed. I have Horizontal irradiance, Tilted irradiance, and Normal irradiance values but ...
2
votes
4answers
117 views

Low-cost solar energy alternatives to power a single appliance in an apartment?

I'm searching for information on solar energy alternatives that are accessible to people like me without having to break the budget. For example, I live in an apartment with a rooftop, and I want to ...
1
vote
1answer
41 views

If water gets on solar panel connector from cleaning or rain will it cause problems?

I have a solar array with 8 panels. There is a slight gap between each panel. At 2 locations string MC4 connectors are placed between the gaps. My question is if water gets on this connector (and not ...
1
vote
1answer
43 views

What is the typical embodied energy of a solar photovoltaic panel?

What is the typical embodied energy of a solar photovoltaic panel, in terms of nominal power output or panel area? The ideal answer would be in kWh/WP, but kWh/m2 would also be acceptable. I ...
1
vote
2answers
66 views

Photo voltaic panels string of 3 kW setup

Am considering installing 3 kVA pv system on my roof top. I am to use a string system on a single inverter. My choice is : 12 by 250 W =3000 W or 10 by 300 W =3000 W Space is not an issue. ...