Judge finds solar power more cost-effective than natural gas

[Ned Hamford]

Oh, so that is how that works.  I'm glad this is a resolved issue.   

Administrative judge makes a ruling in Minnesota for a competitive bidding matter.  That being of course a singular issue with only the record on the record examined... but hey, why not pretend this guy was speaking about the choice in all situations.   

http://io9.com/why-solar-power-is-more-cost-effective-than-natural-gas-1497305827

I'm also pretty sure if something is more cost effective; we don't need a state judge to tell us so.  The matter is really fun as the judge considered existing and 'potential future regulations' in his decision making.     So yah, we raised taxes, directly and indirectly, until this was more expensive, so this is more expensive.  You have got to love government logic. 

Huffington Post does a truly mock worthy summation: "When this independent judge looked at the facts, rather than the hype, he found that solar wins and gas loses. He gave several reasons why solar is the preferred choice when all potential costs are considered." http://www.huffingtonpost.com/lewis-milford/natural-gas-loses-to-sola_b_4556162.html

[Scout26]

They lost me at

Unfortunately it emits dangerous carbon into the environment.

 

Sorry, but if you don't understand fundamental chemistry, then I will not listen.

Second, The administrative judge has a law degree, I presume.  Not a Geology, Engineering, Chemistry, Physics or any other hard science degree.

Moron. 

[Northwoods]

Hey, why are you insulting morons like that??

[brimic]

People like that in Minn are also wise enough to mandate vegetable oils in their diesel fuel- you know stuff that freezes in the fuel lines when it gets cold out..

[Firethorn]

Sorry, but if you don't understand fundamental chemistry, then I will not listen.

Carbon can be dangerous.  Pure carbon can be a fire hazard, explosive if rendered into a powder and dispursed through the atmosphere.  CO2 in excessive amounts can asphixiate.  I'll admit that it's a bit of a stretch but if you're with 'most scientists' on global climate change, more carbon dioxide emitted is dangerous due to the changes in weather patterns, rising seas, etc...

Second, The administrative judge has a law degree, I presume.  Not a Geology, Engineering, Chemistry, Physics or any other hard science degree.

On the other hand, consider the question:  "In the long run, will this specific solar or natural gas generation proposal be cheaper'.  A major consideration of this would be the future legal and regulatory climate.  As such, experience with law and the dealings of legislature would probably actually be more applicable than that 'hard science degree'.

Reading the summary it sounds like he did a reasonable job.  It might sound odd, but I expect that you should consider future regulatory burden in a project that's expected to last 50 or so years.  The current trend is for regulation to become stricter, increasing costs, not cheaper.  Right now solar receives subsidies at various levels, it might not in the future(also the Chinese are currently 'dumping' panels on the market, artificially lowering prices).  The article doesn't give any actual numbers so I can't run my own analysis, so I don't know how much weight he assigned to each factor. 

The formulas are simple in theory - cost of suspected future cost(regulatory or otherwise) multiplied by the chance of it happening, adjusted by when you expect it to happen if it does(40 years from now is cheaper than in 10).

Also, I can't really bring myself to find fault in the judge when there's state law directing renewables to be used first before building another fossil fuel plant.

That being of course a singular issue with only the record on the record examined... but hey, why not pretend this guy was speaking about the choice in all situations.   

Yeah, this is true.  I mean, let's disregard stuff like how he looked at how the solar projects would obliviate the need for $33M of new power lines, how power usage is actually declining in the state, etc...

I'm also pretty sure if something is more cost effective; we don't need a state judge to tell us so.

I figure he got involved due to the proponents of the various projects getting him involved.  Also, utility companies are highly regulated; they probably didn't have a choice short of the judge acting as a 'disinterested party'.

[Ned Hamford]

That being of course a singular issue with only the record on the record examined... but hey, why not pretend this guy was speaking about the choice in all situations. 

Yeah, this is true.  I mean, let's disregard stuff like how he looked at how the solar projects would obliviate the need for $33M of new power lines, how power usage is actually declining in the state, etc...

I think you misread my tone and intent.  The judge made the determination he was called upon to do... judging between a set of presented bids.  The dozen articles I've seen running with the story and the ruling present his determination not in light of the singular project, but as if solar has trumped gas everywhere and forever. 

Although I am concerned about the judge going outside the record with speculation on the future of regulation.  Yes, common sense, everyone sees it coming ect... but as a legal matter, you use the law in front of you.  Legal trends as a projected cost factor are dubious.  But, hey, this was an administrative ruling; so the only standard of review is that there was some standard of judgement. 

[Firethorn]

I think you misread my tone and intent.  The judge made the determination he was called upon to do... judging between a set of presented bids.

I think scout flavored my response.

Solar trumping NG for a major installation, based on price is an interesting precident, even if it's flavored by a hefty expectation of future carbon tax/trading costs.

Although I am concerned about the judge going outside the record with speculation on the future of regulation.  Yes, common sense, everyone sees it coming ect... but as a legal matter, you use the law in front of you.  Legal trends as a projected cost factor are dubious.  But, hey, this was an administrative ruling; so the only standard of review is that there was some standard of judgement.

While I'm neither lawyer nor accountant, I'm a more skilled accountant than I am a lawyer.  As such, potential future regulatory cost is really no different in my mind than the possibility that a tornado will rip the facility to shreds.  It's my job to chose the one that is most likely to be the 'best choice' based on specified criteria(least overall cost in this case).

Considering 'future law' in a criminal or even civil court case would be a completely different matter.

[MechAg94]

Haven't regulations already been increasing over recent decades?  Yet natural gas is still cheaper when available.  Natural gas heat in my house is still cheaper than electric. 

It also really depends on what sort of "installations" you are talking about.  The plant I work at has 4 big recip compressors of 6000 to 11000 HPU.  You aren't going to build a solar farm to run compressors like that.  For one thing, there is no way to maintain that kind of power 24/7.

Solar has it's niche, but it is not for everything.  I am sure this decision was pretty narrow.  The idea that it is universal is silly. 

[Firethorn]

Haven't regulations already been increasing over recent decades?  Yet natural gas is still cheaper when available.  Natural gas heat in my house is still cheaper than electric.

Yes, but consider:
1.  Natural gas used for heating is ~95% efficient, NG used for electricity is going to peak at around 60%, closer to 50% if you want to play with sequestration of the CO2, as it takes power to sequester.
2.  The proposals in the article were for electrical generation, not heat.

Roughly speaking, my thoughts on the matter is to use energy sources for what they're suited for; NG is better for producing heat than electricity.  If you have huge plants burning NG to provide electricity, that's more money you have to pay for the NG you use to heat your home.

It also really depends on what sort of "installations" you are talking about.  The plant I work at has 4 big recip compressors of 6000 to 11000 HPU.  You aren't going to build a solar farm to run compressors like that.  For one thing, there is no way to maintain that kind of power 24/7.

Sure you can.  You might need acres of solar panels, but it can be done.  As for power 24/7, that's what solar thermal with molten salt storage would be for.  Whether it'd be economic at this point is a separate matter(and would probably be slaughtered by alternatives, I'll admit). 

Also, we're back to that this is to produce electricity for the grid - and nationally about 50% more electricity is used during the day than the night.

Solar has it's niche, but it is not for everything.  I am sure this decision was pretty narrow.  The idea that it is universal is silly. 

Agreed.

[MechAg94]

What is the efficiency of solar?  20%?

I can't believe you are comparing a relatively small set of GE steam turbines in size and infrastruction to a solar mirror farm with molten chemical storage for heat?  There is no comparrison in size, cost, complexity, and power output.

Has that molten salt storage thing been put into use somewhere or is it theoretical?  What is your efficiency melting that salt and then generating power from it?  My undersstanding is that solar thermal generates steam to produce power.  Is that not the case?  Your efficiency converting steam to electricity is fairly low.  That is only a portion of the cogeneration method.


Also, for industrial uses, the electrical use doesn't drop off at night so much.  I guess my view is centered around powering an industrial complex, not a suburban neighborhood. 

[Firethorn]

What is the efficiency of solar?  20%?

Doesn't matter; the relativity does.  IE using photovoltiac panels to power electric heating would be incredibly dumb, burning NG to create electricity to do resistive heat would be only a little smarter, burning the NG directly to provide heat or using a solar thermal panel requires the accountants to get their spreadsheets out.

Higher efficiency solar panels means you need to cover less area, which is good as it reduces costs that way.

I can't believe you are comparing a relatively small set of GE steam turbines in size and infrastruction to a solar mirror farm with molten chemical storage for heat?  There is no comparrison in size, cost, complexity, and power output.

Size for power output, maybe.  But I'll remind you that power output is simply a matter of scale, and you'd have the steam turbines in a solar thermal farm anyways. 

And did you miss the 'slaughtered by alternatives'? 

Has that molten salt storage thing been put into use somewhere or is it theoretical?

Gemasolar, Seville, Spain.  20MW

What is your efficiency melting that salt and then generating power from it?  My undersstanding is that solar thermal generates steam to produce power.  Is that not the case?  Your efficiency converting steam to electricity is fairly low.  That is only a portion of the cogeneration method.

Efficiency - What section are you measuring?  The thermal collection part can be over 90%, the steam turbine part would typically be 40-60%.  Yes, it uses steam to produce power.

I'm not sure what context you're using 'cogeneration method' here for.  In my experience 'cogeneration' means that you utilize the energy gathered to do more than just generate electricity.  The coal cogeneration plant near where I work provides both electricity and steam for heating the facilities.  I'm not aware of any major solar cogeneration plants yet produced, though I like the idea.

Also, for industrial uses, the electrical use doesn't drop off at night so much.  I guess my view is centered around powering an industrial complex, not a suburban neighborhood.

Actually, I'm looking at total usage for the grid, not specific classes of users.  Suburban neighborhoods actually use more power at night.  Industrial, as you state, tend towards 24x7.  Commercial though, that's where the real power usage is, being heavily slanted towards the day.

[MechAg94]

Most Cogeneration I see down here burns natural gas to produce electricity and steam.  If you have a use/customer for the steam, great, but otherwise, you use a condensing steam turbine.  I think a lot of coal power plants down here have natural gas turbines that can run as peak power plants. 

As far as industrial, our company has air separation plants that use 60 or 80 MW of electricity 24/7.  If there is a home for the steam, an on-site Cogeneration unit can be very cost effective. 

[Firethorn]

As far as industrial, our company has air separation plants that use 60 or 80 MW of electricity 24/7.  If there is a home for the steam, an on-site Cogeneration unit can be very cost effective.

Bingo.  If you can use the 'waste' heat, the overall process is a lot more efficient, as you can 'effectively' produce electricity at the total efficiency of the system, which can bust 90% depending on type and quantity of heat you need.  This is normally a lot better than the 40-60% you can get out of various traditional power plants where their main concern is dumping all that heat as waste.  Or you can look at it as getting the heat for free.

I've looked into it and I can produce electricity using #2 fuel oil in a diesel generator cheaper than the utility company if I can scavenge most of the waste heat to keep my house warm.  Just can't justify the capital cost yet.

[MechAg94]

But just like a cogeneration plant, it is only cheaper if you can find that dual use. 

Technically, heat recovery is a key part of any power and chemical plant also down to the point where the recovery is not worth the investment or the delta T is not significant.  Then they turn to cooling. 

I have my doubts about your diesel generator idea once you scaled it up to the point of wholesale fuel and heat costs along with full bore EPA environmental reporting, infrastructure, water permits, etc, etc. 

[Northwoods]

I'd love to see those calcs, Firethorn. 

Where I work there 8 engine test cells where the run tests on 13L diesel engines.  5 of those cells use A/C dynos, and when it's absprbing engine power they do use the electricity to partially power the facility.  But the cost of running the engines make it stupidly expensive to run them solely for the power produced.  Grid electricity is MUCH cheaper.

Granted that is not quite the same as a dedicated gen-set, but it's not THAT far different.

[Ron]

The byproducts from an engine are pretty darn corrosive. What would you use to capture the heat? I suspect that whatever is left over after all the heat is removed other than water and CO2 would be pretty nasty.  

Otherwise I love the idea of being self contained or more self sufficient.

[Firethorn]

I have my doubts about your diesel generator idea once you scaled it up to the point of wholesale fuel and heat costs along with full bore EPA environmental reporting, infrastructure, water permits, etc, etc.

The critical point here is that I wasn't talking about scaling it up.  Wholesale fuel I can 'sort of' get since I have a 1k gallon fuel tank already.  And I can only justify it if I'm utilizing the vast majority of the waste heat.

I'd love to see those calcs, Firethorn.

 
Out of country right now, so don't have the original calculations.  Don't even have an electricity bill handy.  It 'helps' that I'm in Alaska and therefore electricity is expensive. $.20 per kwh.

#2 Fuel Oil@$4/gallon, 138k BTU.  1 kwh = 3.4k BTU. 40kwh per gallon. 
Now, a high quality generator will burn approximately ALL of the fuel, but will hit about 30% for transforming it into electricity.  So, in a pure generation mode, you'll only get 12 kwh per gallon, or 33 cents per kwh.  Ouch.  You can survive paying it, but way too expensive.

But remember, Alaska, much more need for heat than cooling.  So we hook the cooling system for the generator up to the hot water pipes for the boiler system as well as putting a heat exchanger on the exhaust.  The important concept to remember here is that every BTU we scavenge here is a BTU we don't have to generate by burning even more oil; IE cogeneration.  How much heat can we pull?  I used 80% - the efficiency of my boiler, rounded down.

This means I'm utilizing 32 of the 40 potential kwh in a gallon of diesel, or 12.5 cents per kwh marginal cost.  Keep in mind that capital costs aren't included in this figure.  That 8 cents saved per kwh means that it'll take 125k kwh to pay off for a system that I'm ballparking in the range of $10k.  Given that I use about 700 kwh/month and figuring I can only use the waste heat for 6 months of the year, you're looking at a straight payoff of 30 years for the capital costs, and the engine won't last that long.  Heck, I haven't even put maintenance into there yet - things like replacing the oil in the generator every so often.  On the other hand, I haven't figured avoided costs like boiler maintenance either.

Where I work there 8 engine test cells where the run tests on 13L diesel engines.  5 of those cells use A/C dynos, and when it's absprbing engine power they do use the electricity to partially power the facility.  But the cost of running the engines make it stupidly expensive to run them solely for the power produced.

Like I was just saying - it doesn't make sense if you only use them to provide electricity.  It makes much more sense if you need the heat energy as well.

The byproducts from an engine are pretty darn corrosive. What would you use to capture the heat?

Part of the heat would be scavenged from the engine's cooling circuit.  More would be pulled from the exhaust using an extremely heavy duty heat exchanger made from acid resistant material.  Ideally the unit would indeed be condensing, but I recognize that the unit to do so would be expensive, and cooling the exhaust that much can lead to interesting airflow concerns.  Ideally the last step before venting outside would be to have a last heat exchange between incoming(normally below freezing) air destined for the engine and the outgoing exhaust.

Otherwise I love the idea of being self contained or more self sufficient.

Since the capital costs are such that it'd never make financial sense from that perspective alone, you have to justify it along the lines of 'I'm getting a backup generator anyways...'.

So if it's $10k for the whole system, I consider the costs for a simple gasoline generator - ~$4k as 'I want backup power'.  After that I look at the increase of going to a diesel generator and hooking it into my fuel oil tank as a 'it's only $x more expensive to be able to utilize my existing fuel tank and cheaper bulk fuel, and not have to worry about running out all month'.  Once I have the diesel generator, going from standby to prime rated generator and adding the heat exchange parts isn't that bad either.

I'm still having to find a 'cheap' prime diesel generator for the core of the system though.

[MechAg94]

I like the concept.  Quite like a lot of industrial applications of one kind or another. 

I would think just placing the generator in a basement would catch a lot of the heat assuming you can manage the exhaust safely.

[Northwoods]

I think you'll find that capturing the heat isn't as easy or as effecient as you're assuming.  Particularly if there's a turbo on the generator.  That already extracts the majority of the useable heat energy.

Also, is addition to routine maintenance remember you'd be running this genset almost 24/365. Most diesels have a lifespan of around 4000-6000 hours.  That's about 1 year for you.  You can overhaul a lot cheaper than buying new, but you usually only rebuild an engine so many times.  And while cheaper, OH's ain't free, by a long ways.

[Firethorn]

I would think just placing the generator in a basement would catch a lot of the heat assuming you can manage the exhaust safely.

I've had that thought, though 'managing the exhaust safely' could be quite the trick, depending.  I also have concerns about how I'd ensure that the exhaust gets outside, even as I'm cooling it while warming the air I'm sucking in.

Though getting the generator into MY crawlspace would be quite the trick - I don't have a full basement, but the 'crawlspace' is tall enough that I just barely have to duck, but it's fully sealed apart from a small access inside a closet.

I think you'll find that capturing the heat isn't as easy or as effecient as you're assuming.  Particularly if there's a turbo on the generator.  That already extracts the majority of the useable heat energy.

Most of the generators I've looded at don't have turbos. Define 'usable' when it comes to heat, and how the turbo would remove my ability to scavenge heat.  For that matter, where does it put the heat such that I can't retrieve it?

Also, is addition to routine maintenance remember you'd be running this genset almost 24/365. Most diesels have a lifespan of around 4000-6000 hours.  That's about 1 year for you.  You can overhaul a lot cheaper than buying new, but you usually only rebuild an engine so many times.  And while cheaper, OH's ain't free, by a long ways.

Actually, this would be incorrect.  Remember, I can only 'profit' when I can use the heat.  So the system would be set up with the house still on the grid, the generator would only run when my house calls for heat.  That means for ~6 months a year it won't be running, and even in the winter it won't be running 100% of the time.  Even then, I'm seeing figures of 20k hours for a prime generator, 4-6k hours would be for a standby generator.  A prime generator will be 1800 RPM, while a standby might be 3600 RPM.

As for the maintenance - that's why I only mentioned 'such as'.  I'm full aware that even larger bits of maintenance would be required, which is why I said that I couldn't justify the capital cost.

Instead I'm looking at things like a stirling engine - which COULD run that long without extensive maintenance, even if it's less efficient on the electrical side.  Higher end would be some of the fancy fuel cell technologies.