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Entries tagged as ‘NREL’

Solar Panel Pricing

April 20, 2009 · 2 Comments

Every now and then I get someone asking me what the cost of our panels is in $/kWh.  I always have to reply that we’re still in our pre-commercial phase of product development, and that we’re not able to give price quotes yet.  We have a really good idea of what we think the panels are going to cost, and we have really good data to back that up.  But until we’re able to prove it (to ourselves and our investors) it’s not responsible to start quoting prices without a long string of qualifiers.  (Put another way, is it a real price if I can’t sell you any yet?)

But I want to make a point about pricing solar panels.

First off, if you’re actually planning a specific solar farm, you really can’t make planning decisions unless you’re able to calculate your LCOE (Levelized Cost of Electricity).  That means you’re taking into account all of the variables that affect the cost of developing a solar farm (land, installation, mounting, inverters, grid connection, system efficiencies).

The best tool I’ve found for this is the NREL SAM (Solar Advisor Model) software available for free.  Calculating LCOE is enormously complex and will always be site specific.  Fair warning, using SAM is complex and frustrating, and if you’re really serious about learning how to calculate LCOE, take a course or find some good online materials to guide you.   Then have someone who really knows what they’re doing review your work.  That said, LCOE is expressed in $/kWh and is the most useful expression of cost when considering a specific solar farm.

Personally, I never trust it when solar panel providers quote $/kWh unless they’re willing to give you the model they used.  It’s site specific and there are hundreds of variables that can have a HUGE impact on the final result.  (At a conference, a speaker tried to get away with “Using standard metrics and a reasonable interest rate, we got an LCOE of…”  Pure weasel words.  Where?  What metrics and what interest rate?  Give me your model or don’t waste my time.)

That said, I hate using $/watt too.  $/watt is slightly more useful, partly because it’s one of the variables you need to calculate LCOE, but mainly because you only need to know how much sunlight they’re assuming.  But $/watt gives you the power production at peak power output.

Consider this:

You want to develop an 1 MW system, and in your region you can expect an average of 5.5 hours of good sunlight per day.

  • A fixed system (that doesn’t track the sun) can generate up to 550 kWh/day.
  • A two-axis tracking system will generate up to 792 kWh/day.

This is assuming the same panels, so the $/watt for the panels is the same for both systems, but the results are very different.  At noon, both systems can produce 100 kW in an hour, so $/watt doesn’t really give you the whole answer.  To get a useful number, you need to know exactly what you’re asking when you ask for a price.  When you get an answer, you need to make sure you have enough information for it to be meaningful.

When we do eventually start talking price, I want to make sure that we’re giving enough information so that people won’t have to jump through hoops to figure out what they ACTUALLY cost.

Categories: About Morgan Solar · Solar Farms/Development · Solar Power
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New World Record for PV Efficiency

September 30, 2008 · Leave a Comment

That is very cool, as has been reported on a number of sites, Scientists at NREL’s Solar Energy Research Facility have broken the record for cell efficiency.  This is great news, and better still that they got this efficiency at reasonably high concentrations of 326 suns.  So, my questions are, how much concentration can these things take and when can I get my hands on some?

The technical details sound interesting and it’s assembled slightly differently to a normal triple-junction cell, so it will be interesting to see how this plays out.

My favourite quote from the article:

The new cell is a natural candidate for the space satellite market and for terrestrial concentrated photovoltaic arrays, which use lenses or mirrors to focus sunlight onto the solar cells.

It seems that every time someone mentions CPV, they add “lenses or mirrors”.  There are other ways to do it, and I would venture to say, better ways to do it.

Categories: Solar Industry · Solar Power
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Better Uses for MIT Solar Storage Breakthrough

August 6, 2008 · 7 Comments

Ideas

Energy Ideas

A news story has been making the rounds for the last week or so, heralding a revolutionary breakthrough for solar power.  The short version, they’ve come up with an amazing new way to separate water into hydrogen and oxygen, using an innovative new catalyst that works at room temperature, low pressures and yields efficient conversion.  Great so far.  They’re touting it as a breakthrough for home solar installations.  This is a brilliant technology, and if it’s as cheap as they claim it will play a huge role in solar.  But not the way they’re saying.  This does not belong in the home.

Here are some articles.

Screen caps from Daniel Nocera’s MIT video.

I really had to spend some time reading on this before I started this post. When I first saw this article starting to pop up in blogs and Google Alerts, I didn’t think much of it. “10 years away” too often means “never”, so basically I lost interest. But the article kept popping up and it seems that they’ve got something useful that really works, and it will probably lead to commercial applications.  So in this case, “10 years away” might actually mean 10 years away.  Cool!

Check out Daniel Nocera’s MIT video for a decent overview of the technology.

I want to be totally clear, I think this is an absolutely amazing technology, and hell, I’ll go one further and say that when it comes out, I’ll invest.  But it’s a bad fit for residential solar and an amazing fit for utility scale solar.  After some thought, I want to address a few points made in discussing this technology.

Point 1: No solar energy at night is what’s holding solar back.

In the video Daniel Nocera says the following:

“It really opens the door for the large scale deployment of solar, because we have an easy way … to store that energy.”

This is just wrong. On the most basic level, we don’t need more electricity at night. We need more in the afternoons during peak demand. If you look at the daily electrical consumption (examples below) you’ll see that the night time price of electricity is a  fraction of what it is during the day.

Typical Daily Demand Curve

Typical Daily Demand Curve

LMP is Location Marginal Pricing, a standardized method of describing electricity pricing.  PJM Interconnect is a regional transmission organization in the North East.  Source: NRELUnderstanding the Economic Value of Electricity Storage: Some Key Drivers.

Hourly Price of Electricity

Hourly Price of Electricity

Source: Healthandenergy.com: Demand Side Management

Solar energy, especially solar energy with tracking capability, or concentrated solar thermal systems with built in thermal storage, produce energy when we need it the most – during peak demand.  Utility scale electrical storage would let solar facilities store the cheap morning electricity generated prior to peak demand, and output more electricity during peak demand.  (Solar thermal already does this by storing heat, but it can only be stored for 6 hours.)

Solar Tracking and Co-Firing Demand Durve

Solar Tracking and Co-Firing Demand Durve

Source: Hal LaFlash, PG&E – Utility-Scale Solar Power Generation Presentation.

Night time electricity is incredibly cheap, and if there is lots of nuclear, geothermal, hydro or wind power in your area, it can get close to free. Wind power is most productive in the evening and at night, so if you really need more power at night, throw up a turbine and you eliminate the need to install (in every home mind you) hydrogen and oxygen storage tanks, fuel cells, water tanks, piping, inverters and whatever else you need to run this system.

Basically, if the big advantage of this is that it provides power at night, it’s solving a non-existent problem.  Solar benefits from storage, but not the way they seem to imply.

But the real thing that’s holding back solar energy is that the cost compared to the power output is still higher than just buying power off the grid.  (Something we at Morgan Solar are working to change soon enough.)  Even if this system was 100% efficient (which is impossible) it would still mean more equipment and more costs for the same amount of power. That they’re suggesting you shift power from when it’s most useful to when it’s least useful, which doesn’t really make sense.

Point 2: This is a solar technology.

After looking at this, reading their website, watching their video etc, it’s fairly clear that this system electricity, and the source doesn’t really matter. This catalyst uses electricity to run the system, not photons, heat or anything else particular to sunlight.  Any electrical source would work.

As cool as this is, it’s not really “solar storage”, it’s electrical storage.  In a home installation, this system would provide MUCH better returns if you used the super-cheap and abundant night time electricity from the grid to store hydrogen that you could burn during the day.

Point 3: This would be cheap and useful for providing nighttime power

There is just no way that this system could be cheaper than a few more wind turbines. There is no nighttime energy crisis. Electricity peak demand is from around 4PM to around 7PM. High demand is from noon to 8:30PM or so. No matter how cheap this system is, there is no way you could reasonably justify the costs of hydrogen and oxygen storage tanks and a hydrogen fuel cell to provide power at night.

Point 4: Getting off the grid is a good thing

I hear many people talking about “getting off grid”. It really sounds better than it is.

The electrical grid is one of the most astonishing achievements of modern society. It’s totally democratic, even the poorest of the poor can be and usually are connected, and it improves absolutely everyone’s life.  Access to indoor light, heat and appliance power helps everyone.  We’ve spent the better part of a century building it for a reason, and it’s so effectively built and managed that we forget about it most of the time.  You plug something it, it turns on.  We only pay attention to it during windstorms or the occasional (very seldom) power outage.

But wanting to disconnect sounds like a good idea.

“If I generate all my own power, then I’m not contributing to whatever bad stuff happens when the utility generates electricity. Carbon, pollution, all of that, I’m not involved if I disconnect…”

Technically true, but what about your surplus power? What happens when your power system breaks down? (Which it will occasionally.) What about the people who can’t afford the up front costs of going off grid?  Sure you can go carbon free if you disconnect, but you can go carbon negative if you stay connected and give back.

Basically, it makes much more sense for us all to contribute to the grid.  So using this to “liberate” yourself from the grid is a non-starter.

Increase our local home production as much as we can, while decreasing our consumption, so we’re giving back more than we’re taking. In this model, a couple of things happen. First, it provides more of a financial incentive for upgrades to the grid that would benefit everyone, and second, it contributes to a more stable, productive and low cost power grid for everyone.  Staying connected and giving back makes more sense than disconnecting.

This hydrogen fuel cell doesn’t generate power, it stores it, and doesn’t do anything to lower household consumption. It’s great if you need a battery back up, or if connecting to the grid isn’t an option, but all it does is store power.

Practical Uses for Cheap Efficient Electrical Storage

Now, to be clear, I think cheap, efficient and reliable energy storage is an amazing thing, and something that we need. But not for storing solar power at home. Here are some smart scenarios for using this breakthrough:

  • Hook an industrial scale version of this thing up to a nuclear power plant, run it at it’s optimal power output 24/7, store power when the grid doesn’t need it and dump the power onto the grid when demand goes up.
  • Hook these up to wind turbines, which are intermittent and unpredictable, so you get a more steady baseline power output.
  • Hook one up at home, charge it up all night, and use it during the day to lower your power consumption during peak demand.

The real value of this in the solar market will be for what’s called Load Shifting.

  • Hook up an industrial scale version of these to a solar farm, so that that the power generated in the morning (which isn’t worth much) can be stored and dumped onto the grid in the afternoon and early evening when it’s at peak demand.  At home, this makes no sense, on a utility scale, it’s brilliant.

Another amazing application would be local demand management.  They spend millions of dollars topping up local power dips and trying to get the power from the big utility stations to the widespread grid.

  • Put neighbourhood versions of these in trouble spots, store hydrogen when there’s lots of power and then top up the grid when you start facing brownouts or rolling blackouts.

In all these cases, you’re taking power when it’s cheap and not in demand, storing it, and then using it when (or where) it’s actually needed.  But power at night? Don’t need it, don’t want it, it’s nearly free already, so why use daytime energy to make it?

This is huge, this is a major breakthrough, if this works and people can use this technology to make utility scale systems that stock-pile energy and deliver it when needed, they’re going to make billions.  But installing these in the home, tied into residential solar – pass.

For a rediculously detailed economic analysis of storage for renewable energy, check out this report from the NREL.

Categories: Solar Industry · Solar Power
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