Photovoltaics and Electric Steam Boiler for refurbished home

Larry Weingarten

Hello, Like @hot_rod , I've been involved with solar thermal for a while. I have a blog where I wrote an article on a low tech solar system that avoids many of the problems of solar. Here is a link to that blog: http://www.larryweingarten.com/blog Look for the post on 12-30-18 titled "Another Solar Myth Bites the Dust". Basically, solar doesn't have to be really expensive or difficult/time consuming to maintain.

Yours, Larry

Jamie Hall

PMJ said:

@FuriousGeorge ,



You seem convinced then that no significant breakthrough in power transmission is possible. I count nothing out in any area. I say I can't pick where the next breakthough will occur any more than I could pick a single stock to put all my money on. I am very sure our government can't pick it either.

We're together again, @PMJ ! What's happening?

More seriously -- on local siting, which @FuriousGeorge seems to prefer. For many things it work well enough -- in and exurban and rural areas. As it happens -- all over the world -- only a minority of the people live there. One has to have solutions which work for the people of North Dakota, or Queens, New York, or sub-Saharan Africa, or Beijing or who knows where. One size most assuredly does not fit all, whether it's energy production, water supply, wastewater disposal, food production... you name it. Keep and open mind! On new technology, who would have imagined, 30 years ago, EHV DC interties -- just to cite one example?

FuriousGeorge

@PMJ

Not just solar, although that is the main player on the renewable side.

Even if there were a major breakthrough to increase efficiency in making and moving power, it would likely benefit any form of production. Given the choice and the price per watt, most Americans would rather get their power from solar over coal. Being able to put a solar plant out in the desert and efficiently move the power to the coasts will solve the energy density and availability problems with solar. Of course, this requires replacing the massive current grid with a smart grid that uses tech we can't yet make cost effective on the desktop scale, so we are talking decades.

The fact is that solar is cheaper right now than coal, and the industry employs more people. The discrepancy is almost certain to increase.

While I personally think nuclear is part of the solution, some people are never going to get past the fact that you can never 100% rule out a meltdown, accidental or otherwise. Also, it isn't particularly cheap if you want to build it safe. After Fukushima, I'm assuming this is more of a problem, not less.

This doesn't even begin to address the issue of carbon emissions with coal. Most people believe this is a bad thing. I don't see how sequestering it will bring down the price per watt, anymore than you capturing and burying chimney smoke will make using a fireplace more practical.

Jamie Hall

I give up.

FuriousGeorge

@Jamie Hall

That's not even getting into the fact that a finite resource becomes more scarce as you use it, which means over time the price must go up relative to inflation. Our consumption will not start going down. No matter where you are in the world, this is a fact of life that you can't engineer your way out of in perpetuity.

Look at Dubai and the mideast in general. Not one is sitting on more oil than them, but these hippies see the writing on the wall. Again, that should be a red flag. It's one thing to say what should be policy, it's another to be in a position to own the consequences.

Plus, real solar plants use steam, not PV, which obviously makes them way cooler.

Phil53

Interesting discussion, but kinda academic cause I don't know of any electric steam boilers for residential use. I know Slantfin makes one for water, but I'm not aware of anyone that makes one for steam.

PMJ

FuriousGeorge said:

@Jamie Hall

That's not even getting into the fact that a finite resource becomes more scarce as you use it, which means over time the price must go up relative to inflation. Our consumption will not start going down. No matter where you are in the world, this is a fact of life that you can't engineer your way out of in perpetuity.

Look at Dubai and the mideast in general. Not one is sitting on more oil than them, but these hippies see the writing on the wall. Again, that should be a red flag. It's one thing to say what should be policy, it's another to be in a position to own the consequences.

Plus, real solar plants use steam, not PV, which obviously makes them way cooler.

@FuriousGeorge ,

I get that you are quite optimistic that you can forecast how these things will play out. Things fundamentally technical have that appearance generally; that is that they must have entirely logical solutions.

My experience and observation is that what actually takes place is mostly not at all logically predicted before hand. So many technical things have been learned entirely by accident. Then those new things allow positions to suddenly be taken that previously were simply unthinkable. Each discovery shines a light on the subject from a new angle, illuminating possibilities previously quite hidden from view.

Also, the concept of "finite resource" is quite relative - more related to the cost to retrieve than anything else. Overwhelmingly most of what is in the earth's crust is not even considered in resource estimates - simply because the current cost to retrieve is currently unworkable. Those costs do change, however, and sometimes quite dramatically. I won't be betting against any resource in the long term on that basis.

In keeping with my original point I am not telling you that you are wrong in your predictions. Also in keeping with my original point please note I'm not making any.

PMJ

Jamie Hall said:

PMJ said:

@FuriousGeorge ,



You seem convinced then that no significant breakthrough in power transmission is possible. I count nothing out in any area. I say I can't pick where the next breakthough will occur any more than I could pick a single stock to put all my money on. I am very sure our government can't pick it either.

We're together again, @PMJ ! What's happening?

More seriously -- on local siting, which @FuriousGeorge seems to prefer. For many things it work well enough -- in and exurban and rural areas. As it happens -- all over the world -- only a minority of the people live there. One has to have solutions which work for the people of North Dakota, or Queens, New York, or sub-Saharan Africa, or Beijing or who knows where. One size most assuredly does not fit all, whether it's energy production, water supply, wastewater disposal, food production... you name it. Keep and open mind! On new technology, who would have imagined, 30 years ago, EHV DC interties -- just to cite one example?

@Jamie Hall ,

I never thought we were really actually that far apart on anything. I'm with you though it can feel like it sometimes.

Leonard

I'm in NH, hard to get excited about solar thermal for heating. Stood in bright 2pm sun in February, didn't feel any heat on my face. But I suppose it can help a bit in April, and make DHW in summer.

Lot of solar PV on roofs here, thought about it but I've got lot of trees shading my roof. I want the trees, yard would get too hot to use in summer without them.

hot_rod

Leonard said:

I'm in NH, hard to get excited about solar thermal for heating. Stood in bright 2pm sun in February, didn't feel any heat on my face. But I suppose it can help a bit in April, and make DHW in summer.

Lot of solar PV on roofs here, thought about it but I've got lot of trees shading my roof. I want the trees, yard would get too hot to use in summer without them.

Must have been a windy day:)
Trust me, if the sun is shining on you, energy is being transferred.

We spent years trying to cool down over-heated passive glass sunrooms in winter months,

Brewbeer

An uninsulated brick building should be heated by steam. Any other type of heating system will not feel comfortable when it is 5F outside.

Also, I have had a PV system on my roof for the past 3 years. Zero maintenance required to date. Yes, you can wash the panels if they get dust covered, but that really isn't necessary in New England, as we get more than enough rain to keep them clean. Yes, they do get snow covered, but the PV system doesn't make much power in the winter anyway, and the snow slides off once sunny weather returns. In my state (massachuestts), PV ONLY makes personal economic sense under the following conditions:

1) you purchase the system (no leasing);
2) you plan on living in the house for at least 7 years; and
3) you can take and use the tax deduction.

If those aren't guaranteed, don't buy a solar PV system for the purpose of saving money, because you won't.

hot_rod

Doing some or all the work yourself helps make the numbers work. Many of the "regular" posters here do their own installations. if you are comfortable with the hands on, hire someone to do the design and sizing.

I installed my own PV, bought modules at wholesale cost, got some micro inverters free from an installer that upgraded on a recall, had a master electrical size the wire, conduit and breaker, so my PV system was easy to rationalize, my power provider did an inspection.

Everyone needs to make enery decisions on system based on their wants, needs, and budget.

95°F SWT can heat a space as comfortably as 215° steam when properly applied, it's more about what YOU want.

Low temperature distributions opens more doors IMO heat pumps, solar, mod cons running 90%, etc.

As much as I enjoy ST, the PV does have more year around use. i use electricity all day, every day. PV prices are crazy low right now. With micro inverters you basically feed into a breaker, with code approved disconnects, etc. super simple.

Chris_L

Brewbeer said:

In my state (massachuestts), PV ONLY makes personal economic sense under the following conditions:

1) you purchase the system (no leasing);
2) you plan on living in the house for at least 7 years; and
3) you can take and use the tax deduction.

If those aren't guaranteed, don't buy a solar PV system for the purpose of saving money, because you won't.

I am also in MA and agree on the first point, but would caution on the other two.

My PV system had a payback of less than 5 years. That was due to the large incentives available at the time. The 10-year subsidy of approx. 30 cents per kWh generated will be far more valuable than the tax deduction. But that has gone away for new residential installations in MA.

You really need to look closely at what is available to you where you plan your installation.

As for generating steam from solar PV, I don't think so, as much as like my old steam boiler.

The OP sized a 50 kW PV system. I translated that into about 3000 square feet of panels. You'd need a very large roof for that.

Also, the incentives in MA are based on historical usage not some presumed future electric heating system. I can't imagine any state incentives for the needed amount of production.

But I'd love to hear about a residential, electric steam boiler. Anyone?

hot_rod

Mr Steam builds large electric steam generators for steam rooms

Leonard

Think reason steam might feel more comfortable in SAME air temperature room is direct IR radiant heating of you by the radiator, when your close to it.

I have FHW heat , turned aquastat down from ~ 200 to 145 deg, noticed room FELT colder, but room thermostat read same ( I gave it a day to stabilize). My desk is against wall with a baseboard. Pushed aquastat back up a bit and it felt warmer.

Issue seems to be localized heat near baseboard/radiator VS average room temp.

hot_rod

My guess would be a higher delta between you and a steam radiator?

With ceiling, floor, or wall radiant all the surface area is a radiant surface and as such will warm anything within the sight, much like the sun. If all surfaces are at or slightly above skin temperature comfort is near ideal. Some humidity may need to be added or subtracted, air movement for odor control, to be a true comfort system instead of just a heating system.

I think it comes down to personal preference really, between various types of hydronic, including steam, emitters.