Total beginner wants to install solar on rooftop

[cyrille]

Hello,

I have a 1 story secondary house with a 30° roof with a south west orientation at 1000m altitude where I would like to put some solar panels.
The main aim for these panels is to keep the temperature in the house during the winter months and heat the hot water tank to save $$...
If it can, in addition, provide some power in case of main power failure, it would be a plus. But I am not planning to install battery system ($$) power failures where I am are not that frequent.

The roof has around 25m² of usable space and I am planning to install around 2KW of panels.

I am a capable handyman (I am building the house after all!), but I am completely new to solar stuff...

Hence, I have a number of questions:
- Most of the solar panels I find these days are the 100W flexible type. Are they suitable for installation on rooftops? if yes, how do you install them? (I have a european wavy tile roof, not a US shingle)
- What about electrical connections. Are they standard connections coming out of the panels? going all the way to the inverter?
- Do you have advice on the inverter. Ideally, I will want something that can help me pilot/control my heaters (3 to 4KW between the heaters and hot water). Hence I will need to be able to programmatically condition things (if temp>8°and solar is present, then use solar power to power alternatively the various heaters, if temp<8°, then power heaters, even if there is no solar to keep from freezing. but if I am in the house, then heat all the time, even if no solar)... But I have not found system that indicated that they could do that... Would I need to create my "control" (using an arduino or somehting like that?)

Thanks for all the info you can give me.
Cyrille

[bcroe]

You could consider something like what I do to heat with solar. Panels are
the most economical, 250 to 300 watt range. Inverters send whatever energy
is collected but not used to the grid for Net Metering credit. Most of the energy
I use in winter was collected in summer.

All heating and cooling is done with the latest generation, internal variable speed
inverter type Heat Pump. These HPs multiply the energy supplied several times,
the difference between impractical and practical. There are no batteries.

You will need to get a handle on expected numbers, BTUs, KWHs and so on to
build anything that actually meets your needs. good luck, Bruce Roe

[peakbagger]

Flexible panels typically do not last long, almost every company who has manufactured them in the US went out of business.

[J.P.M.]

Hello,

I have a 1 story secondary house with a 30° roof with a south west orientation at 1000m altitude where I would like to put some solar panels.
The main aim for these panels is to keep the temperature in the house during the winter months and heat the hot water tank to save $$...
If it can, in addition, provide some power in case of main power failure, it would be a plus. But I am not planning to install battery system ($$) power failures where I am are not that frequent.

The roof has around 25m² of usable space and I am planning to install around 2KW of panels.

I am a capable handyman (I am building the house after all!), but I am completely new to solar stuff...

Hence, I have a number of questions:
- Most of the solar panels I find these days are the 100W flexible type. Are they suitable for installation on rooftops? if yes, how do you install them? (I have a european wavy tile roof, not a US shingle)
- What about electrical connections. Are they standard connections coming out of the panels? going all the way to the inverter?
- Do you have advice on the inverter. Ideally, I will want something that can help me pilot/control my heaters (3 to 4KW between the heaters and hot water). Hence I will need to be able to programmatically condition things (if temp>8°and solar is present, then use solar power to power alternatively the various heaters, if temp<8°, then power heaters, even if there is no solar to keep from freezing. but if I am in the house, then heat all the time, even if no solar)... But I have not found system that indicated that they could do that... Would I need to create my "control" (using an arduino or somehting like that?)

Thanks for all the info you can give me.
Cyrille

Are you in North America or somewhere else ?

Either way, since you're a newbie to PV, I'd start with the basics, Get a copy of: "Solar Power Your Home for Dummies". This isn't a pitch but while solar is not rocket science, it's not the same as electricity or HVAC as you may know it.

Get the basics of home PV down. The book is one good way to start getting background info. The book is ~ $25 U.S. and available from bookstores or Amazon. There is also a free online PDF of an older version. It's a bit dated but still good for the basics.

Before you go buying stuff that'll wind up being inappropriate or unusable for your application, get your rough loads and your goals for the PV in place, read the book and then come back here and ask questions.

Then, after that (not before) take a look at something called "PVWatts". It's a user friendly tool on the net that's pretty good at preliminary sizing and design of residential PV systems. Read ALL the help screens a couple of times, get the inputs as close to what you think you want and your situation and location and make a few runs.

Then, come back here and ask questions your self education will create.

From the type of questions you're asking, I suspect things will go a lot faster in information transfer and you'll get more out of the answers you get here as well as save a lot of time/toil/tears if you're up to speed on the basics. There's more to PV than you are aware of at this time.

Welcome to the neighborhood.

[cyrille]

Hello, Thanks for the info, I will get the book.

I am in France.

From a dimentionning standpoint, they are a couple of solar arrays installed in the village, so I was planning to get their produciton curves to get an idea of J delivered by solar panel W installed.
As stated, my main purpose is to reduce my electrical heating cost in winter. Here again I have data from my current power use... Unfortunately, energy sent back to the grid bring in little to nothing here, it might as well be lost OR be stored as extra heat in the house (see bellow)

When I first looked at this around 1 year ago, rigid panels where what you found on aliexpress or amazon... Now, it seems that only flexible are left, hence my question on flexible...
I understand how much easier they are to handle from the seller and shiping standpoint... but to install on a wavy roof I will need to dig deeper to find a source of solar pannels...

My last question was about appliances control from the inverter.
I am a SW engineer, so I know and understand programming...
In my case, I would like to setup some "complex" rules on what appliances will be able to take power at any given time, with various "modes" and the like. Are they any (cheap) systems that do that? it would need "input channels", "output switch controlers" and a "programation" system...
if no, which systems will allow me to get the information (current production, current draw...) so that I can create my own system...

Cyrille

[Cshama]

Something that I ignored until I got my pretty huge solar array installed is that it’s a lot cheaper to save electricity then to make it.

For example I now have a heat pump water heater which is 5 times more efficient compared to the traditional water heaters. I also have a heat pump HVAC system and heat only by electricity. I used to use at least $6k a year of oil.

The solar stuff can make sense but unsexy stuff like heat pumps and insulation are much more important.

And using the 100w flexi panels would be a big mistake.

[SunEagle]

Something that I ignored until I got my pretty huge solar array installed is that it’s a lot cheaper to save electricity then to make it.

For example I now have a heat pump water heater which is 5 times more efficient compared to the traditional water heaters. I also have a heat pump HVAC system and heat only by electricity. I used to use at least $6k a year of oil.

The solar stuff can make sense but unsexy stuff like heat pumps and insulation are much more important.

And using the 100w flexi panels would be a big mistake.

I agree. Going with flexible panels would be throwing good money away. A rigid panel will be less costly and last much longer. If there aren't any rigid panels to be found for now then maybe going solar is not the right thing for the OP to do.

[cyrille]

Hello,

Well, looks like I will have to keep looking for normal panels then!!!!

With regard to heat pump. Are we talking air/air or air/water?
Air/Air seems to be in the 1500$ range. And I have 4 rooms to heat (2 bedrooms, on main room and one bathroom). Although I can probably setup an air circulation system and use only 1 heater, that is still a lot of money. The air/water are >$4000 and require water based heaters which are much harder to install..

I was planning to use electric floor heaters which cost around 130$ per Kw. and install around 2kw in the house... these last essentially forever (the heat pump, where I am, also must be inspected very 2 years or so by a professional, which will cost me an extra $150 or so every 2 years)...
Yes, the heat pump is better from an energy standpoint... but it seems that it might not be worse the $... unfortunately
And I can easely crate a computer system that will inteligently control my 4 heating zones... will the heat pump work inteligently with the inverter?

Cyrille

[Will792]

Hello,

Well, looks like I will have to keep looking for normal panels then!!!!

With regard to heat pump. Are we talking air/air or air/water?
Air/Air seems to be in the 1500$ range. And I have 4 rooms to heat (2 bedrooms, on main room and one bathroom). Although I can probably setup an air circulation system and use only 1 heater, that is still a lot of money. The air/water are >$4000 and require water based heaters which are much harder to install..

I was planning to use electric floor heaters which cost around 130$ per Kw. and install around 2kw in the house... these last essentially forever (the heat pump, where I am, also must be inspected very 2 years or so by a professional, which will cost me an extra $150 or so every 2 years)...
Yes, the heat pump is better from an energy standpoint... but it seems that it might not be worse the $... unfortunately
And I can easely crate a computer system that will inteligently control my 4 heating zones... will the heat pump work inteligently with the inverter?

Cyrille

Heat pumps mentioned earlier were for domestic water heaters. There are plenty of companies making split heat pump systems that you can use. Big companies in that space are Mitsubishi, Daikin and LG. Most of these companies have controllers that allow control over internet so you can program every header unit to your liking. I do not see why split system requires biannual maintenance.

A conventional PV system is attached to a roof with rails, L brackets and some hardware matched to the type of roof. US municipalities require design that can handle highest expected wind and snow load. Even if your location is not strict with design it is in your interest to have a system that would survive the most extreme expected weather conditions.

You did not mention if your roof pitch is sufficient for snow clearing on its own. That is something you need to keep in mind, unless you do not expect to get snow.

overall economics of PV system without having credit for exported electricity are tough. It would be very difficult to save money by reduced electricity consumption since substantially percentage of generated electricity has zero return for your initial investment in hardware and your time.

[cyrille]

Hello,

My roof pitch is around 60%. The snow does not really clear out by itself... but we have not had much snow recently. However, when here, it stays...

There is another building (the town hall) not far from mine with solar installed. I was able to get their production data for the last couple of months:
This is the production in KWh, per day, per KW of solar panel installed (they have 5KW)
nov 1.7
dec 2.9
jan 3.8
feb 4.3

This give me around 2~3h of heating at 1KW per day if I have 1KW of solar panel installed.
Over the 4 or 5 winter months, I can hope to save around 100€ per year (elec @ 22c/KWh). If elec keeps going up (Ukraine war), maybe more...
So, if I want to get my €€ back, I need to get the solar panels dirt cheap! or I need to do it thinking about the environment, and not my money

Cyrille

[J.P.M.]

Hello,

My roof pitch is around 60%. The snow does not really clear out by itself... but we have not had much snow recently. However, when here, it stays...

There is another building (the town hall) not far from mine with solar installed. I was able to get their production data for the last couple of months:
This is the production in KWh, per day, per KW of solar panel installed (they have 5KW)
nov 1.7
dec 2.9
jan 3.8
feb 4.3

This give me around 2~3h of heating at 1KW per day if I have 1KW of solar panel installed.
Over the 4 or 5 winter months, I can hope to save around 100€ per year (elec @ 22c/KWh). If elec keeps going up (Ukraine war), maybe more...
So, if I want to get my €€ back, I need to get the solar panels dirt cheap! or I need to do it thinking about the environment, and not my money

Cyrille

The best and most foolproof way of looking after the environment and still look after your own interests is to take a longer, wider view to expending the least amount of financial resources to accomplish well considered goals. The environment - whatever that entity entails - will then take care of itself. That's just the way it is.

The rub is in the goals.