Hot answers tagged

6 votes

Electrical design for large property

That "free" wire is actually a bit of a millstone around your neck in your situation The problem with your "free" 4/0 wire and quadruplex (4/0-4/0-4/0?-4) is that it's somewhat too ...
user avatar
6 votes

Sharing solar energy

Here's something you need to know: solar panels will not keep your house electricity on in a power outage. When the grid power is out, your solar panels are useless in most cases. Normally, this ...
user avatar
5 votes

Using solar to heat water

A common design in my area is a heat exchange tank upstream of a traditional gas or electric water heater. They use ethylene glycol (antifreeze) that circulates by thermosiphon action from a solar ...
user avatar
  • 33.4k
5 votes
Accepted

Solar installer

Depending on the region of the world you inhabit, your system may not be accepted in a grid-tie configuration. In Florida, USA, the local utility is required to examine and sign-off the installation. ...
user avatar
  • 9,293
5 votes

How big of a solar panel is needed to run a 300 watt water pump?

Here's the problem. Virtually all products are built on the assumption that they will be run on utility mains AC power. That assumption permits economies in design: There is no need to "...
user avatar
4 votes
Accepted

Why does the Tesla PowerWall operate at 350v - 450v?

The Powerwall is/will be based on the lithium ion battery technology used in the Tesla cars, so instead of a few large lead acid batteries (like in PV battery banks) it will contain a zillion tiny ...
user avatar
4 votes
Accepted

What is required to connect solar panels to my home without connecting to the grid?

Typical grid connected installs of solar panels on homes need a couple of items to get them to work (it's not just lets slap some panels up there and wire it into the house). Solar panels are DC (...
user avatar
  • 4,356
4 votes
Accepted

Making a Solar Power Battery Backup Unit

You have the basic concept down. Your challenge will be sizing. What's the minimum possible load you can put on the system? For instance, don't use an inverter to run lighting. Run the lighting ...
user avatar
4 votes
Accepted

How can I economically switch between two home power sources?

If you are OK with manual transfer operation, what you're after is called a "select circuit" manual transfer switch -- they're pretty readily available, for anywhere up to 12-16 circuits. Reliance ...
user avatar
4 votes

Solar Water Heater Exchanger Removal, Glycol Removal

I have been an avid recycler in the Portland, Oregon, area for decades. Portland is no slouch when it comes to environmental awareness and concerns. After replacing my auto's antifreeze mixture, I ...
user avatar
  • 12.1k
4 votes

Spacing between solar arrays

You don’t want one row of panels to place the next row in shade. You need to make a balanced choice about panel spacing... too close and you lose useful solar energy... too far and you have too much ...
user avatar
4 votes
Accepted

How to identify electrical panel busbar rating

This is a 125A panel From the labeling on your panel, in particular the note about field upgrading 100A mains to 125A by replacing the main breaker and the meter-to-main-breaker wire jumpers, we can ...
user avatar
4 votes

AC can only go one direction

This is something the inverter's most likely doing, not your wiring Grid-tie solar inverters are designed to feed power into an operating electric grid, and thus need a grid AC source to synchronize ...
user avatar
4 votes

How can I evaluate solar panels to power night lights in areas that don't get direct light?

Maybe explore Power over Ethernet (POE) as an option. If the run is under 100 metres (328 feet) from the barn then you can get up to 15 watts per run of cable. All you need is a POE injector per ...
user avatar
  • 6,826
3 votes

How can I economically switch between two home power sources?

There's nothing electrically wrong with that proposal*, and it certainly is low cost - the plugs will be about $10 a pair. Wether extension-cord plugs are allowed in permanent wiring is a question for ...
user avatar
  • 39
3 votes

Regulations 2015 NEC regarding 12/24 volts DC, New DC wiring Light/+in my old." I'm Scared "

Jon, First of all, I want to make a couple of points, A home owner can do any wiring or electrical on his own home so long as he is not actually tying it into the power grid and he does it up to ...
user avatar
3 votes

What is required to connect solar panels to my home without connecting to the grid?

In stark contrast to some statements seen here, in parts of Europe it is a big trend even for non-electricians to put 1 or 2 photovoltaic modules to the balcony or elsewhere with an on- grid ...
user avatar
  • 2,364
3 votes

Is there a type of interlock (transfer switch) that can be used for a generator OR solar panels?

Simply put a box and splices in the middle of the feeder Here's the rub -- transfer for a generator works differently than transfer for a hybrid solar setup (which is what you're probably envisioning ...
user avatar
3 votes

Options for Running High End Computer on Old Circuit

TLDR: Pay your landlord to add a 20A dedicated circuit for this PC. Fuggedaboutit. 1350W is just too much. Remember, you're talking 1350 watts at the low voltage DC side - you have conversion ...
user avatar
3 votes

What kind of inverter do I need for an inductive load?

It's easier to teach a violinist the bongoes than the other way 'round. You should be shopping for an A/C unit with "soft start". This is one of the reasons for these units to exist - ability to ...
user avatar
3 votes

What kind of inverter do I need for an inductive load?

It is not that the compressor motor is inductive, but that, at startup, it draws far more current than while running. This is a characteristic of most electric motors, but is exacerbated that until it ...
user avatar
3 votes
Accepted

Subpanel and grounding for solar shed to off-grid cabin

2-2-2-4 is fantastic stuff and a regular recommendation from me. Heck the stuff is the price of #10 copper and carries 90A instead of 30A, what's not to like? I have seen several prominent home off-...
user avatar
3 votes

Subpanel and grounding for solar shed to off-grid cabin

Try 2-2-4-6 or 2-2-2-4 MHF instead If your mind is set on #2 Al for the hots, then I can fix your cable problem quite simply: get MHF, not URD. Mobile home feeder cable can be used for everything URD ...
user avatar
2 votes

solar tubes to heat room

You can want whatever you want to want, but that won't make it practical or efficient or cost-efficent (which comes back to practical.) There are at least 2 things that might be called a "solar tube" ...
user avatar
  • 132k
2 votes
Accepted

No hot water even if heating elements work (solar/boiler combination)

If the hot water is hooked up to your faucets, then hot water should eventually come out regardless of the re-circulation stuff. That is, unless the check valve is the wrong way or the pump isn't ...
user avatar
  • 193
2 votes

Would it be entirely crazy to cover my lawn with solar panels?

I don't know about "Crazy" but there are a few issues you should consider: Cost This is obviously going to vary a lot depending on where you live and how big the yard is, but you're probably talking ...
user avatar
  • 13.7k
2 votes
Accepted

Is Solar Heating of Pool worth it? Especially after Time of Use (TOU) electric rates are introduced?

Heating a swimming pool is pretty much an ideal application for solar water heating. Relatively small delta-t requirements in mild weather means you can get high output from low cost solar collectors, ...
user avatar
  • 1,172
2 votes

Sizing electrical wire from Solar Panels

I am assuming that you have 220V going to the barn? As far as wire size, industry standards say to aim for 1 - 2% voltage drop, but running 5000W, 200ft on #8 wire @ 220V results in just under 3% ...
user avatar
2 votes

Photovoltaic installation: does it make sense (or is possible at all) to get a bigger inverter than the power output of the installed panels?

You are right, that contractor doesn't know what he is talking about. Most inverters will produce power at low wattages as long as the Vmp of the string (maximum power voltage) doesn't fall below the ...
user avatar
2 votes

PVC solar 2" pipe joints degrading from ultraviolet...something I should anticipate more of?

PVC (plumbing) is not rated for sunlight exposure and needs to be painted or otherwise shielded from sunlight. PVC (electrical) is not rated for plumbing/pressure use, but is UV resistant. So, if ...
user avatar
  • 132k

Only top scored, non community-wiki answers of a minimum length are eligible