Solar power

[CptFalcon]

So does anybody here work on a complete off-grid or partial grid tie in system. The reason why I am asking is b/c I finally got enough funds to start my own project. I am currently looking into 4 125watt panels, and enough batteries to fill up at least 1.5 KW worth of power. I currently looking at a potential contractor.

And to keep this on topic with the forum, my PSU is an Antec Earthwatts 500watt PSU what 80%+ efficient.

So anybody ponying here up for clean, and relatively cheap (rebates baby!) power?

 

[BillParrish]

We have several hydro systems (one solar as well) in operation here that I have engineered for friends. So while I am not an expert on solar panels I can recommend controllers and batteries.

For batteries, if you want to go top of the line (and I recommend nothing else) look to Rolls/Surrette. IMO there is no other choice for a serious system.

For a charge controller, I recommend Morningstar.

For inverters I recommend Outback.

However these installations are for 100% off grid (the only power) and so being the only power available there is no scrimping on quality. Much less expensive stuff is out there.

One thing we learned the hard way is that many controllers advertise/indicate you can monitor the system with a PC, however once you buy you find the software is not ready.

Be sure and check your current state laws. The rebates have expired and not been renewed by the legislatures in many states.

This stuff is not rocket science anymore dont overpay for basic electrical wiring you could easily do yourself, the manuals for the controllers typically include very good instructions on how to set up the basic system and are available for download if you want to just learn about basic setups.

inexpensive "disconnects" used for the power disconnect at outdoor Central Air units etc. run about $10 at home supply centers and make the most cost effective "switches" to disconnet things for maintence or shutdown. A small mobile home electrical panel with a few breakers and an main, is nice for power distribution if you are not going to tie into an existing panel.

If you generation exceeds usage, instead of dumping the excess power into diversion load consider (you will still need the diversion load) rigging up a relay/electronic timer so that when the controller goes into diversion mode (batteries charged, excess power being dumped) you kick in a relay that cuts on a secondary hot water heater that acts as a preheater for your primary hot water heater.

 

[CptFalcon]

Does anybody here know anything about solar panels that I should know. I don't know what I am looking for. This is a pretty big project especially for me.

 

[Michael Daly]

Do a lot of web surfing on the issue. It's too big for this forum (not to mention off-topic).

In general - don't get overly obsessed with efficiency numbers. Amorphous PV is cheap (relatively) and low efficiency (relatively) and just requires more surface area for the same net power. Polycrystalline PV is more efficient and requires less area but is more expensive. Monocrystalline is most expensive, most efficient and ends up requiring roughly the same area as polycrystalline! This is because the packing of the rectangular PC cells is greater than the circular MC cells and the difference in coverage is roughly the same as the difference in efficiency. Hence, if you're squeezed for area (e.g. roof size) getting the "most efficient" monocrystalline is not the most cost effective - you'd likely get a better deal on polycrystalline.

 

[DryFire]

You're also going to want to calculate/lookup the angle at which the sun's rays hit at your latitude and aim them so the rays and panels are perpendicular.

Solar panels are not the cheapest or even the best way to save energy. Consider adding overhangs to south-facing windows such that direct sunlight in the summer and enters in the winter. Adding more insulation, better windows, better appliances, a heatpump with a higher SEER rating, etc....

It's better to reduce the electrical load of your house before wasting your money on solar panels.

Also, you may want to buy solar thermal collectors for heating hot water (and potentially your house) as they are both cheaper and more efficient--though it's not really fair to compare their efficiencies directly as one produces heat and the other electricity; yummy exergy. If you're interested Apricus was the supplier of choice for solar thermal collectors in the last solardecathlon.

 

[[Spectre]]

(not to mention off-topic).

If you guys want to talk about it I am not going to shut it down.

 

[andyOCZ]

Interesting thread here. I have been thinking about going solar. Thanks for the info. I do agree that conserving energy through lower wattage lighting and improved thermal efficiency is the best way to start.

As far as being on/off topic; We are discussing a "power supply", albeit one that will power your PC power supply.

 

[Cobalt2112]

Any good sites that can talk about charging batteries off the grid in case there are frequent outages in my area and I wouldn't want to fry my PC's PSU (or more)

In other words, Gel Cell batteries (I hear that theyre all the new rage now) as well as something like 6K inverter. I would need to power several PCs which are on all day plus some of the house's electrical systems (fridge, lights)

I would be looking for details on how to connect the current public grid to my battery setup, then have an active trip (I would like near transparent) where my PCs wont go down if there is an outage... yes I can connect UPS batteries, but I guess Im looking for the equivalent of a 6K to 8K PSU (whole house version)

We have several hydro systems (one solar as well) in operation here that I have engineered for friends. So while I am not an expert on solar panels I can recommend controllers and batteries.

For batteries, if you want to go top of the line (and I recommend nothing else) look to Rolls/Surrette. IMO there is no other choice for a serious system.

For a charge controller, I recommend Morningstar.

For inverters I recommend Outback.

However these installations are for 100% off grid (the only power) and so being the only power available there is no scrimping on quality. Much less expensive stuff is out there.

One thing we learned the hard way is that many controllers advertise/indicate you can monitor the system with a PC, however once you buy you find the software is not ready.

Be sure and check your current state laws. The rebates have expired and not been renewed by the legislatures in many states.

This stuff is not rocket science anymore dont overpay for basic electrical wiring you could easily do yourself, the manuals for the controllers typically include very good instructions on how to set up the basic system and are available for download if you want to just learn about basic setups.

inexpensive "disconnects" used for the power disconnect at outdoor Central Air units etc. run about $10 at home supply centers and make the most cost effective "switches" to disconnet things for maintence or shutdown. A small mobile home electrical panel with a few breakers and an main, is nice for power distribution if you are not going to tie into an existing panel.

If you generation exceeds usage, instead of dumping the excess power into diversion load consider (you will still need the diversion load) rigging up a relay/electronic timer so that when the controller goes into diversion mode (batteries charged, excess power being dumped) you kick in a relay that cuts on a secondary hot water heater that acts as a preheater for your primary hot water heater.

 

[Michael Daly]

I'm sure Bill knows more about this as he's current and I only "dabble" (for 30+ years now).

Gel cell batteries are good for some applications as they require less maintenance than wet-cell. AGM (absorbed glass mat) are like gel cell but with less gel that is absorbed in glass mats on the surface of the lead plates. These are better than gel cell in one specific way - they are the safest as they are leak-proof. They are the only batteries that are not highly restricted by hazardous materials (hazmat) rules for shipping. That's why they are chosen for almost every consumer UPS - they can be sent to the retailer/consumer by mail, including air, without hassle.

However, for large(ish) off-grid applications, and for really big UPS applications, wet-cell is the better choice. It's not unusual to see 2VDC (that's two, not twelve) wet-cell batteries used to make up an array of batteries for power storage.

The difference between a wet cell and a gel/AGM installation is the size, maintenance, cost etc. If you want low maintenance, AGM is good. If you want the best overall performance and don't mind the maintenance, and need lots of capacity - you want wet-cell. Consult an expert (better - become an expert; if you play with this for a while, you'll know why being your own expert is a good idea).

If you're serious about off-grid and you need 24/7 power, you should consider wind as well and have a auto-starting generator.

In some areas, wind is better than solar. In others, solar alone works well. Around these parts, I would go with a combined wind+solar - local to me we get lots of sun in the summer and lots of wind in the winter, so a hybrid wind/solar arrangement is often the cheapest/most reliable.

Since even the best solar and/or wind arrangement will eventually not meet 100% of the requirements, a backup generator (one that starts itself when required) is essential. Gas (petrol), propane, Diesel/bio-diesel, etc are available depending on your fuel availability and preference.

BTW - search the web and start reading. I don't know of a single good site for info, but lots of info is out there. Eventually, you'll start to become an expert.

 

[CptFalcon]

I'm sure Bill knows more about this as he's current and I only "dabble" (for 30+ years now).

Gel cell batteries are good for some applications as they require less maintenance than wet-cell. AGM (absorbed glass mat) are like gel cell but with less gel that is absorbed in glass mats on the surface of the lead plates. These are better than gel cell in one specific way - they are the safest as they are leak-proof. They are the only batteries that are not highly restricted by hazardous materials (hazmat) rules for shipping. That's why they are chosen for almost every consumer UPS - they can be sent to the retailer/consumer by mail, including air, without hassle.

However, for large(ish) off-grid applications, and for really big UPS applications, wet-cell is the better choice. It's not unusual to see 2VDC (that's two, not twelve) wet-cell batteries used to make up an array of batteries for power storage.

The difference between a wet cell and a gel/AGM installation is the size, maintenance, cost etc. If you want low maintenance, AGM is good. If you want the best overall performance and don't mind the maintenance, and need lots of capacity - you want wet-cell. Consult an expert (better - become an expert; if you play with this for a while, you'll know why being your own expert is a good idea).

If you're serious about off-grid and you need 24/7 power, you should consider wind as well and have a auto-starting generator.

In some areas, wind is better than solar. In others, solar alone works well. Around these parts, I would go with a combined wind+solar - local to me we get lots of sun in the summer and lots of wind in the winter, so a hybrid wind/solar arrangement is often the cheapest/most reliable.

Since even the best solar and/or wind arrangement will eventually not meet 100% of the requirements, a backup generator (one that starts itself when required) is essential. Gas (petrol), propane, Diesel/bio-diesel, etc are available depending on your fuel availability and preference.

BTW - search the web and start reading. I don't know of a single good site for info, but lots of info is out there. Eventually, you'll start to become an expert.

Yeah, I have replaced all the bulbs in my house with Florescent bulbs and saw our bills go down about 9%, and all the stuff in our house is Energy Star rated. I would like to tap into the meter to see how much power we consume in one day so I could better see how much we do actually use on a daily basis.

I was thinking of starting small at first; a few solar panels with a small array in the basement and then upgrading as time (and money) came by. My school is adopting a program to install solar panels and they are replacing every computer in the school with EE ones with the new AMD 4850e CPUs.

I am still looking though.

 

[Cobalt2112]

I ask about the Gel batts because I saw an ad on TV about the Gel batteries being better and have the capacity of several "conventional" batteries. Are they just blowing smoke?

I'm sure Bill knows more about this as he's current and I only "dabble" (for 30+ years now).

Gel cell batteries are good for some applications as they require less maintenance than wet-cell. AGM (absorbed glass mat) are like gel cell but with less gel that is absorbed in glass mats on the surface of the lead plates. These are better than gel cell in one specific way - they are the safest as they are leak-proof. They are the only batteries that are not highly restricted by hazardous materials (hazmat) rules for shipping. That's why they are chosen for almost every consumer UPS - they can be sent to the retailer/consumer by mail, including air, without hassle.

However, for large(ish) off-grid applications, and for really big UPS applications, wet-cell is the better choice. It's not unusual to see 2VDC (that's two, not twelve) wet-cell batteries used to make up an array of batteries for power storage.

The difference between a wet cell and a gel/AGM installation is the size, maintenance, cost etc. If you want low maintenance, AGM is good. If you want the best overall performance and don't mind the maintenance, and need lots of capacity - you want wet-cell. Consult an expert (better - become an expert; if you play with this for a while, you'll know why being your own expert is a good idea).

If you're serious about off-grid and you need 24/7 power, you should consider wind as well and have a auto-starting generator.

In some areas, wind is better than solar. In others, solar alone works well. Around these parts, I would go with a combined wind+solar - local to me we get lots of sun in the summer and lots of wind in the winter, so a hybrid wind/solar arrangement is often the cheapest/most reliable.

Since even the best solar and/or wind arrangement will eventually not meet 100% of the requirements, a backup generator (one that starts itself when required) is essential. Gas (petrol), propane, Diesel/bio-diesel, etc are available depending on your fuel availability and preference.

BTW - search the web and start reading. I don't know of a single good site for info, but lots of info is out there. Eventually, you'll start to become an expert.

 

[Michael Daly]

What kind of "conventional" batteries? Are they talking about NiMH, NiCd, Li-Ion, wet cell, etc? In general, TV ads are a good source of pure BS.

Gel-cells are good for many tasks. They require less maintenance than a wet-cell but retain the advantages of lead-acid batteries. They also have some of the drawbacks, such as poor power to weight ratios.

If you want a battery with, say, 2 Ah capacity, an SLA (sealed lead acid, either gel-cell or AGM) will only allow about 50% discharge repeatedly for long life with longest life with less discharge. If you discharge an SLA to about 20% remaining capacity, it will only last a few hundred charge-discharge cycles. Note that this is for deep-discharge batteries. Using 50% as a rough average, that means you need a 4Ah SLA for 2Ah usable capacity.

NiCd or NiMH, OTOH, will be quite usable at 95% repeated discharges for their entire life. In fact, NiCd work best under these conditions. Therefore, a 2Ah battery pack will give you a 2Ah usable capacity. Hence the capacity is fully usable and the NiXX will be much lighter. Hybrid cars use NiMH for these reasons - experimental hybrid cars 40 years ago only had lead-acid batteries and suffered from weight problems.

On the other hand, if you want 500Ah total capacity, you should pretty much stick to SLA or wet-cell since they will be cheaper and easier to manage. That much capacity in NiXx will require a lot of matched cells bundled together at a high cost.

PS - you guys don't have to quote the entire message.

 

[CptFalcon]

Sorry guys I have no new updates at all so far. I was thinking of getting one of those back-up ones and experimenting with that but I couldn't bring myself to spend $880 on a small battery and a meager panel.

Has anyone here had any success with installing a system?