Is PV economical in Mass?

5 Posts
Nov 15, 2008 10:58 am
Is PV economical in Mass?

Looking at some of the altE kits, and doing the math vs. National Grid's supply & delivery prices, it doesn't seem that 4-4.5 hours of sun per day makes a PV system economical.  Is anyone doing this in MA?  Am I using bad numbers?  Suggestions and comments are welcome!

Thanks,
Mike G.
 
Nov 16, 2008 05:37 am
Re: Is PV economical in Mass?

Opinions are like bellybuttons, everybody has one.
Some can even have a "classic" opinion.....
However, it is a widely excepted opinion that an off grid residential system would cost the same as a lifetime of paying for grid power. An exception to that would be a remote off grid home where the homeowner would have to pay the utilities to set many poles and run miles of wire. The PV industry tried to change this by coming up with battery-less grid interactive/PV/inverter systems. All in all, photovoltaics is very expensive no matter how its advertised. Why else would one of its selling points be that you can get government assistance in the form of tax credits and buy back programs for utilizing it? Not to mention, you would be saving the planet Earth.
Personally, I think that last point is moot because all it really does is enable the energy addiction.

Look at it this way, does your power provider generate electricity by burning coal? How many of your years on Earth do you expect to pay for grid power? How many $ per year? 40 years at $1000.00 a year? What kind of PV system could you put together for $40,000.00?
Ask yourself, "How is it that the human race thrived on the planet Earth for thousands of years without electricity as we know it today, but I cannot live without electricity?"
If you are allready on the grid, re-learn how to live without electricity, slowly wean yourself off of it or as much as you can manage then think about PV and other alternatives. Other enablers include LP and natural gas, fuel oil and kerosene, wood and coal, but of course why not just let the power company burn coal for you right?

How did the human race do it for thousands of years? What are the basics to human existence on Earth?
That would depend on region first of all so I will use New England.
What people are/were indigenous to that region prior to utilitized electricity? Wampanoag perhaps? How did the Wampanoag live "off grid" before the "white settlers?"
http://www.mnsu.edu/emuseum/cultural/northamerica/wampanoagculture.html (I offer my respects to the Wampanoag and their ancestors on their Day of Mourning, for it is all I have to give.)
Of course we can't have 6.5 billion people living that way world wide now can we? The affects of that would be disastrous to Earth, to say the least; but aren't the affects of 6.5 billion people just as disastrous to Earth the way we are living today? Why else would "saving the planet" be another selling point for RE?
http://www.history.com/states.do?action=detail&state=Air%20and%20Water%20Pollution&contentType=State_Generic&contentId=58538&parentId=earth
One more question for you, and this is a little off subject but one I feel needs to be ask. How is it that the people of this American nation allowed the U.S. government to set into motion, the means of turning America into a socialist republic?
http://www.nytimes.com/2008/10/14/business/economy/14treasury.html?_r=1&oref=slogin
There used to be the U.S.S.R. or, the Union of Soviet Socialist Republics, now its just, Russia. Will it soon be that U.S.S.R. stands for the United States of Socialist Republics? The answer may lie in Article 1, Section 8, Clause 18, of the Constitution of the United States of America. McColloch vs. Maryland
http://caselaw.lp.findlaw.com/data/constitution/article01/44.html#1
« Last Edit: Nov 16, 2008 05:45 am by Thomas Allen Schmidt »
 
19 Posts
Nov 20, 2008 05:00 pm
Re: Is PV economical in Mass?

Michael,

Mr. Schmidt's well-made points aside for the moment, let me offer some insight into the question you posed. (Full disclosure, I work at altE, though not in sales!)

Short answer: Yes, solar PV is doable even in MA. As you might expect, you'd need a bigger PV array in MA to produce the same amount of energy (in kWh) as you would need in Phoenix, but it is certainly doable. It's worth noting that the solar resource you mentioned, "4-4.5 hours of sun per day" ought to be qualified. We measure the solar resource in "sun hours" or "peak sun hours", which is not the same thing as hours of sunlight. The idea of sun hours is based on an industry standard that is used to rate modules and quantify available solar energy at different sites. The standard is Standard Test Conditions (STC) and is based on the rough approximation of solar irradiance received at the earth's surface: 1,000 Watts per square meter.

In order to estimate production of a given PV array, we need to know what it can be expected to generate under "ideal" conditions. Since PV modules AND locations are rated under the same standard, we can use a location's sun hours to estimate an array's output at a specific location, within standard parameters (unobstructed sunlight reaching the array between 9AM and 3PM, for one).

The 4-4.5 sun hour range for most of Massachusetts is an annualized average. Take a look at an insolation (sun hours) chart for a MA site for a whole year and you'll notice that, in summertime, the peak figure can exceed 7 hours; in winter, that number can drop below 3 hours, depending on location. So don't be fooled by the seemingly low number, since it doesn't represent actual "hours of sunlight". STC is simply the industry standard for comparing apples to apples (and modules to modules and site to site).

Cheers,

Ben
 
5 Posts
Nov 20, 2008 08:25 pm
Re: Is PV economical in Mass?

Not to belabor the point, but I wasn't asking whether or not it was doable, rather whether or not it is economical.  I'm aware that the value of 4-4.5 hours isn't "hours of sunlight", and I didn't say that it was.  "Hours of sun per day" was my shorthand for "(annualized) average daily hours of useful solar energy available at my latitude."

I understand that latitude affects insolation, and I don't question the sizing adjustments.  By my math, the 1.3kW kit would yield about 1.3kW x 4.25 hrs/day x 30 days/month x .80 efficiency = 132kWh per month.  Using National Grid's ballpark of about $0.21/kWh (including generation and delivery), an installation of that size would save me $28 per month in terms of net metering and reduced grid demand.  Understand that I'm using averages, and there will be seasonal variability - but that's why averages are useful: they normalize those swings.

The kit costs a little more than $9k.  I figure that (roughly) miscellaneous extra installation costs (permits, labor, etc.) would about offset any expected rebates or tax credits.  With an investment cost of $9k and a monthly savings of a bit less than $30, it appears that the payback period is 300 months, or 25 years!

So, my question is: am I missing something?  IS PV ECONOMICAL in MA?  Greening-of-the-world aside, is it a good financial decision?  I can more easily see $9k spent elsewhere on "saving the planet" - it's about the premium between a quality hybrid car vs. the standard alternative.

Further comments welcome and sought!
Thanks,
Mike
 
184 Posts
Nov 21, 2008 08:19 am
Re: Is PV economical in Mass?

Michael,

I decided to "ease" my way into solar PV by starting with a small system.  I've made several upgrades over the years, and I've also made a series of home improvements and purchased energy-efficient appliances.  To make a long story short; as my PV capacity goes up, my consumption goes down.  Someday, I'll be generating as much as I am using. When that happens I'll unplug from the grid, perhaps only reconnecting during extended periods of cloud cover.

Since you're from the east, the electricity you consume probably comes from coal that was mined by blowing the tops off of mountains.  Not only are mountains being lost, the trees and overburden are dumped in the valleys and streams below.  Streams, rivers, and groundwater sources are being destroyed.  Personally, I don't want to contribute to that destruction.  Laws that are supposed to protect the environment, and reclaim mined lands, are not being enforced.  Typically, a thin layer of dirt goes over the rock and mining debris.  Grass might grow, but trees will not.  It's unstable, and not at all suitable for building.  Just imagine the loss of habitat that is occuring as a result of these practices.  Mountain people have been displaced, and their source of groundwater destroyed.  Why is this allowed to happen?  Politicians get big contributions from the coal industry.  I could go on and on, but just Google MTR mining and find out for yourself.  It will make you sick.

I'll continue to invest in PV as my budget allows, regardless if it makes sense from a financial standpoint.  I hope others will do the same. Since we can't depend on politicians to do the right thing, we have to do it ourselves.  http://solarjohn.blogspot.com

John
   
 
19 Posts
Nov 21, 2008 09:52 am
Re: Is PV economical in Mass?

John,

As it happens, most of the electrical power in MA is produced by natural gas-burning plants, not coal-burning. See:

http://www.iso-ne.com/nwsiss/grid_mkts/enrgy_srcs/index.html

Your point is well taken, of course, about environment v. RE cost. I believe that any true economic analysis of RE systems and costs MUST, in some way, include "green" accounting: that is, it must account for carbon releases and offsets.

[Soapbox moment:] For too long, America (and the world) has plowed ahead as though there were no consequences to our energy-related activities; now we face dire consequences of that willful ignorance. So long as green accounting is ignored, the answer to Michael's completely valid question about the economy of a PV system will always be a highly qualified "Yes, but only in the long term". As you can imagine, our staff get that question daily from potential customers. The ones who recognize the total costs of energy production, such as you and an ever-increasing community of others, know that it's a "good deal". [off the soapbox]

Of course, the up-front costs ARE high and that means a high financial bar for those interested in adopting some form of RE generation (versus the lower-cost efficiency improvements you mentioned). Once some form of carbon tax is implemented (and it surely will be), the costs will effectively drop.

~Ben
 
19 Posts
Nov 21, 2008 10:05 am
Re: Is PV economical in Mass?

Micahel,

I didn't mean to insult your knowledge of PV systems; I was offering the clarification about sun hours because, as you might imagine, most of the queries we receive are from those who do not know the distinction. So please accept that my explanation was for the benefit of others who may be following this thread.

Yes, the straight economics do indeed look bleak. So I guess you have your answer: PV is not (yet) for you. Please read my response to John's comment (below). The main point is this: at this point in time (pre-Carbon Tax), investment in a PV system is a LONG-TERM investment, not a short-term one. If your financial event horizon doesn't go out into the 20+ years hinterlands, then, no, it's not for you. Others' plans do go that far (John's, for one, it seems), and they become eager adopters.

I personally think that short-term, dollar-of-energy-offset-for-dollar-of-system-cost economics are not realistic, but I can certainly understand how homeowners would arrive at the same conclusion that you do. All your calculus means is that PV is not for you, plain and simple. Doesn't mean it won't be for you someday; doesn't mean you can't right now begin to impact your energy costs through prudent conservation and efficiency efforts... which, by the way, will make the economics of your future PV system that much better.

By the way, have you looked at the actual rebate estimate spreadsheet from Commonwealth Solar? Download it here:

http://www.masstech.org/SOLAR/#

(click button at right "Step 3. Estimate Rebate"; in the popup window, click to download the "Residential Rebate and Savings Estimator" [Excel file])

That way, you won't be guessing about the economics of your own proposed system and you'll be empowered to answer your own question (and not rely on shameless PV advocates like me!).

Cheers,

Ben
 
5 Posts
Nov 21, 2008 11:18 am
Re: Is PV economical in Mass?

Ben,

I appreciate your insight, and no offense was taken.  Basically, my family and I are doing what we can in a modern, well-built (but conventional) house to reduce our energy consumption .  In the next two years, I'm planning a few big-ticket upgrades: a new (to us) car, a solar DHW system, and solar hot air systems for our upper floor and my separate workshop.  I'm trying to figure out (and I think you've confirmed it) whether or not to spend the money TODAY on PV or, rather, invest it in a similarly green purpose (such as a hybrid car).  Thank you for your thoughts. 

One additional offset which almost eliminates the need to calculate the payback period is the value such a PV system would add to resale value of our house.  I assume that since I'm considering a grid-tied system without batteries, the useful lifetime of the installation is measured in decades, right?  That would DRASTICALLY simplify the economics.

Mike
 
19 Posts
Nov 21, 2008 12:16 pm
Re: Is PV economical in Mass?

Mike,

You are on exactly the right path, I would say, by pursuing the solar thermal systems and efficiency increase first. (I'm a big fan of the solar air heaters!) And for carbon reduction, the car is a major one (mostly related to scheduling use); my mom got a Prius and does mostly short trips in her town.

Yes, in almost all markets, PV systems will increase the resale value of the home; that part of the calculus of system economics is often overlooked (probably most folks considering systems aren't planning to move anytime soon so they don't think about it?).

And yes, useful lifetime is measured in decades. PV modules themselves, though certainly not indestructible, are built to last. Most are warranted to produce within 80% of rated (label) power for 20 or 25 years, so you can bet they're going to last at least that long (in our classes, we love to point out that the first "modern" solar cell made, by Bell Labs, is still functional-- over 50 years later... of course, it's kept in a lab!). No moving parts means much reduced chance of failure. And per standards in effect in CA (which end up being applied in other states, too), GT inverters must be warranted for 10 years. Batteries, as you've guessed, are the "weak link" in system longevity, and constitute a very substantial investment. But then, when you're OFF the grid, what are your options for storage?

Cheers,

~Ben
 
462 Posts
Nov 22, 2008 11:36 am
Re: Is PV economical in Mass?

Michael, you should reread John D.'s answer. Why invest such a large sum of money up front for some PV? Start small and grow. Buy enough now to run any blowers or pumps for the systems you plan to do first. Then they will completely solar! Or size it a little bigger to handle your current heating system or dedicated circuit of lights and such, for emergency use, should the main power go out. Then invest in additional systems as you get the funds. Then you can take them with you easily if you ever move.
 
5 Posts
Nov 22, 2008 03:20 pm
Re: Is PV economical in Mass?

Tom,

You've confirmed what I was thinking: I might be able to do both (the hybrid and the starter PV setup).  This might be a different thread, but what parts of a system are capacity-driven?  That is, aside from the batteries (if any), what components need to be replaced/upgraded as I add generating capacity?  Also, per your comment regarding emergency use during a power outage, I understand that grid-tied systems automatically disconnect during a power outage to avoid injuring unprepared line workers.  What switch/disconnect do I need in those circumstances?

Thanks!
 
462 Posts
Nov 23, 2008 11:38 am
Re: Is PV economical in Mass?

Mike, the system would not be grid tied, so the power you make is the power you use. If you are starting small you may have to check with your power company about grid tie. They usually require a specific size system to be installed in order to get their money back. 
 The biggest part of a PV system is the batteries, so a good investment here is the first thought. Buying similar batteries at the same time is also usually the thing to do.(Same with PV) But size your system according to what you plan to operate. You may be able to get away with one battery, a 100 Watt or more PV panel, a small controller, and a small inverter just to operate the pump and blower and a light or two. Then if battery capacity is sufficient, you can add multiple inverters and 12/24 volt loads.
 If you know what you would like to operate in the future, and know the power they will require, you should think about purchasing a larger controller, since their prices are moderate, and/or battery bank to start.
 Then it's a matter of adding PV to recharge your batteries faster. You can also use such systems totally separately in case of failure of one. 
 
19 Posts
Nov 24, 2008 09:21 am
Re: Is PV economical in Mass?

Allow me to add a note of caution with respect to battery-based (stand-alone) systems. Battery banks tend to operate only as well as the weakest battery in the bank. A single bad cell in a bank of multi-cell batteries can eventually drag the whole bank permanently down to the level of that bad battery. And even the best-kept batteries degrade steadily over time; hence, it's not a good idea to add battery(ies) to a bank that has been in use for even more than a few months. I urge you to read information about batteries, such as our series of articles here:

http://howto.altenergystore.com/Library-Articles/Solar-Electric-Power-or-PV-Systems/Batteries/c19/

Batteries are expensive, dangerous and don't easily suffer fools!

Cheers,

Ben
AltE
« Last Edit: Nov 24, 2008 09:31 am by Benjamin Gorman »
 
Nov 27, 2008 10:06 am
Re: Is PV economical in Mass?

"Is Pv economical?", "What's the payback time?", "Is there enough sun in my area?". These are all questions I had, and questions I hear from many people I speak with. We would all like to do our part to help the environment and become free from dependence of fossil fuels and foreign oil. But to dish out thousands on something that we can get along without gives us just reason to pause. To help myself better understand these questions (and actually find some legitimate answers!) I began taking classes, online courses, and hands-on workshops to better understand the technology, design principles and skills. Well, asking the above questions to my many different instructors, I found as many different answers to agree that PV is worth it. One argument that sticks with me the most is, "What else do we buy, that we expect a payback from?" When I bought my new truck last June ($26,00.00), what was it worth the minute I drove off the lot? Maybe $22,000? What's it worth today,  5 months later? How about the payback on a pair of shoes? Or a new computer? The other thing is that power costs will continue to rise. I live in Massachusetts too. This time of year it's often hard to believe that the sun ever shines here, but we still get more sun than Germany and look at what they've done with solar!! Good luck with your project!
 
Nov 28, 2008 12:17 am
Re: Is PV economical in Mass?

Is that snow? Oh, hey Michael, you know, one of the terms I haven't seen in this thread is,
"The number of Hours of Equivalent Full Rated output (Power) of a PV module per Day."
Phew! Somebody needs to come up with an acronym or something for that phrase.
As I am sure you are aware PV modules don't make full rated power as soon as sunlight hits them. Power output starts out low in the morning rises to a peak at noon (even at noon a PV module may not produce full rated power) and dwindles off into the afternoon and evening. Basic stuff, right? For New England, this ranges from a minimun in December of 2 hours to a maximum of 7 hours in June. An annual average would be 4 HEFRPD's. (Needs work I think.)
So if we go with that and dream up an example of a 1000 watt PV array or, 1 kW PV array, an annual average might produce 4 kWh per day or 1460 kWh per year. What do you pay for grid power $0.0912 per kWh? If so that would sum up to $133.15 per year. Even at $4 per watt, the PV modules alone for that 1000 watt array would cost $4,000.00 divided by $133.15 I come up with 30 years.
Nope, must not be snow. Just wishful thinking.
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/
Don't let this discourage you though. Sometimes, taking a leap of faith has rewards of its own. Just so you know, I took a leap of faith when I made the chouce to live without any electricity at home for over 25 years. It wasn't easy but it is possible. As hard as some of those early years were, I cherish the memories of it all. It gave me an insight as to how life must have been for early American settlers. Some of them where refered to as New Englanders.
« Last Edit: Nov 28, 2008 12:20 am by Thomas Allen Schmidt »
 
3 Posts
Nov 30, 2008 10:48 am
Re: Is PV economical in Mass?

Mass. currently has the Commonwealth Solar rebate program that offers up to $6.50 / watt rebate for installing a PV system.  That along with the 30% Federal tax credit can help pay for a significant portion of your system.
Check out
http://www.masstech.org/renewableenergy/commonwealth_solar/index.html

-JT
 

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