Is PV Solar Practical?

While this article is about a city in California rather than somewhere in Nicaragua, I found the analysis very useful. (Note that I got to this site following a link about PV solar in Nicaragua which turned out to be no more than a press release.) This article talks about Murrieta contracting for PV solar for the city hall.

Unlike so many articles that conclude that PV solar is good—or bad—by ignoring the facts that might change the conclusion, this one offers the information so you can see how they reached their decision to go with this system. Of additional interest is that the approach is not based on a capital investment by the part of the government. A private company is providing and installing the equipment and then recovering its costs over the life of the power contract.

Commercial Solar Power approached the city a year ago, offering free installation and equipment accompanied by escalating rates over 20 years. Year one, the city will pay .145 cents per kilowatt/hour. The rate will increase 3 percent each year, to .254 cents at the end of the agreement.

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Ironic That There

is not more of this in California. The PV industry has quite a bit going for them there. Plenty of sun, very high electric rates, and mandatory buy back of excess power by the electrical vendor (major players are SoCal Edison and LA Dept of Water&Power.

There is a very large Israeli operation that generates power by focusing the sun with tracking mirrors onto a pipe that runs the length of the mirror array. The pipe contains a mineral oil that drives turbines connected to generators. They've expanded the field several times. They are profitable, but only because they are able to sell their power at guaranteed prices.

The death knell to all of this is probably the recent advances in recovery of natural gas deposits within the US. At this point we have a 100 year supply and the exploration goes on. Natural gas is easily converted to electricity. No question that the up and down voltage conversions, and transmission losses wastes quite a bit, but if the price is right to begin with ?? And, it's steady, unlike wind and PV.

The Keystone pipeline will further drop the price of oil, and make the market more dependable. This won't happen during the Obama administration (precisely because it will lower oil prices and guarantee some measure of oil security), but approval will probably be the first act of the incoming Republican administration.

Oil is fungible, and with the US being the biggest consumer, lower oil prices will mean cheaper gas and fertilizer in Nicaragua -and everywhere else.

The Republicans may not win since they tend to mess up

The issues with Keystone are a bit more complex than you seem to be stating:

I suspect that lower oil prices would mean that more Americans bought more gasoline, and that China and India would buy more gasoline, and that without Venezuela, Nicaragua would be better off doing what Brazil did and developing bio-fuels which made tremendous sense for a 4 season climate.

Rebecca Brown

Gas Prices Are Reaching

towards $5 /gallon in some markets. I heard someone today predict a $6 /gallon price (in all fairness I have to disclose that it might have been Lou Dobbs on Fox News). Gas was $1.84 /gal when Obama took office. And we really haven't opened the Iranian can of worms yet. Even is Iran is reduced to selling to India and China we will see a speculative spike in world oil prices.

This factor alone (gasoline price) will derail the economic recovery and doom the president's re-election prospects. There WERE some issues with Keystone, and people simplistically equate more oil with cheaper oil. The Canadians are not going to give us any discounts, but we would have the additional security of an assured supply. The North Dakota people sell their premium oil at a $32 discount because of the lack of a pipeline to bring it to market.

You could be right about the Republicans; I choose to see it as a healthy debate that is pushing Romney to the right. Once the primary is finished Romney will move back to center and the knives will be out -and not for fellow republicans.

This is the first time I have been grateful for Hugo Chavez' assistance to Nicaragua.


is romney inevitable? sanctorum already has a nickname the left thinks villifies him... maybe rick has the right stuff? pun intended....

"Maybe, just once, someone will call me 'sir' without adding, 'you're making a scene." -Homer J. Simpson

Interesting article about Solar Panels

What would the life expectancy of panels be Nicaragua? I suspect much less than 30 years.


A radio guy made a similar comment about a particular brand of data radios which are made in Canada and they are shown mounted on a tower covered with ice. Nicaragua just doesn't have particularly extreme weather.

In the case of solar panels you have doped silicon with wires connected to it embedded in glass (more silicon). They are really like a huge semiconductor diode. The typical reason solar panels fail is that the seal fails. Older panels had silicon rubber seals held in place by an aluminum frame. Today, many are laminates.

Today's panels come with a guarantee from the manufacturer for from 20 to 30 years. Typically you will see output power guarantees. For example, 90% of rated capacity for 10 years, 80% for 25 years.

My Concern has to do with 2 things:

1. the Human factor. Potential Damage due to ignorance or deliberate actions. 2. corrosion and/or mold: Things tend to rust very easily in many parts of the country, the rest of the country is prone to mold Both are not good for electronic components (Not the Silicon, but wiring connections).

Generally on the Efficiency of Solar Power "Systems":

The total energy consumption to manufacture the panels and the batteries required to store the energy (how many batteries for how many panels) must be less than the total output of the system over the lifetime of the panels including the the number of batteries required over the lifetime of the panels - if 20 years life span of Panels(on average) then one will need about 4 to 5 battery changes (assuming a 4 to 5 year life span of the batteries). Anyways, you get the drift... I have no supporting evidence on this one way or another. But the question is valid. I cannot find any data on the amount of energy required to manufacture batteries. I did find this article though, discussing the life cycle of batteries:

Well, ...

The total energy consumption to manufacture the panels and the batteries required to store the energy (how many batteries for how many panels) must be less than the total output of the system over the lifetime ...

Not necessarily. You are, in many cases, paying for convenience. A gasoline-powered car is a good example of something that is very energy inefficient compared to other transport modes but we select it for convenience. Some say it saves time whereas others point out that if you take the numbers you much work to buy it, maintain it, insure it, fuel it, ... it actually does not save time.

Battery technology is (finally) changing but there are both long life lead-acid ones (if used properly) and of Edison sells which are virtually impossible to kill. I understand your concerns based on the typical short-term thinking I see all the time but that does not have to limit the technology. For example, electronically limiting how much the battery can be discharged before the system shuts itself off is easy.

There are also alternatives to batteries. For example, pumping water is a good way of storing energy. And in many cases, storage needs may be minimal. For example, businesses use most of their energy when it is daylight, air conditioning demands are higher at mid-day and so forth.

PV solar is clearly not the answer for everything but there are lots of low-hanging fruit that can be picked with it. I remember some years ago there was an electric vehicle charging facility built into a parking garage. Batteries were charged in the cars from free solar energy while the car owners were at work.

As for manufacturing batteries, it is a lot like aluminum cans. Making something new (from ore) requires many times more energy than recycling.


PV Solar is most efficient/Green when the energy is used immediately. i would like to see more DC appliances on the market. most DC appliances are sold on the marine market and tend to be Very expensive. Combination Wind and Solar would be the ideal, with little or no storage of power using the current (affordable) battery technology.

Solar PV Continues

to fall. I haven't seen the promised 68 cent /watt panels from Korea yet (promised this month) but $1 /watt isn't bad.

Xantrex now has a combo grid tie/standalone inverter for someone looking to the future.

I found an interesting remark in PhotoVoltaics Design & Installation Manual" in chapter 11.5:

"The standard kilowatt-hour meter used by the vast majority of residential and small commercial customers accurately registers the flow of electricity in either direction. This means the "netting" process happens automatically. The meter spins forward in the normal direction when the customer needs more electricity than is being produced and spins backward when the consumer is producing more electricity than they need in the house of building".

My understanding of this concept is that you could use Union Fenosa as a massive battery, pushing the meter backwards during the day (assuming you had a significant PV installation) and using their power at your production cost at night and during rainy weather. One WOULD have to be careful not to push the meter too far backwards . . . what they don't know isn't going to hurt them, right??

I've always felt that the ultimate PV installation would have a grid tie if possible to minimize the battery depth of discharge.

I'd still have my own battery installation (who wants to depend on Nicaraguan power), and I've been investigating forklift batteries as a possible solution. Newer ones are available in 48V (used to be a 36V standard), one advantage would be you would never have to worry about theft. We recently let ours go a year unattended and when we finally got around to checking water, we used 9 gallons of distilled water to top it off. Now, these are big batteries, steel cased, and would be a chore to move to the site, but they are designed for precisely the type of duty that a standalone PV installation encounters. Once there and properly maintained they might be good for 25 years. Even a good sized installation wouldn't need more than a couple of them.

in the states...

at what point does a pv retrofit make sense? i have 15 more years here...

"Maybe, just once, someone will call me 'sir' without adding, 'you're making a scene." -Homer J. Simpson

Defining "Make Sense"

As John points out, there are tax credits, marginal rates, reliability, and, most important, future electrical rates. Much of this is political games. For example, while the concept of what a tax credit is trying to address (reducing the need for more expensive sources of energy) is sound, the implementation is politically manipulated. The same goes for how much the government spends to secure and maintain foreign petroleum sources.

If you take all the politics out of the picture, the question really becomes one of resources. In the case of PV solar it is relatively easy to figure out. The panels are mostly silicon and contain nothing exotic. There is no shortage of silicon in the world. Other components are but a small part of the picture and nothing more exotic than what you find in a computer. The electric grid is already there and can easily handle huge quantities of input from private PV solar installations.

Thus, today, PV solar makes sense. That is, it will reduce the use of resources that are in short supply and only use those in abundance. As for financial sense, that is, unfortunately, just a political question.

yes, political questions enter the equation

but i was thinking about personal out of pocket costs....

i came across this today:

"Maybe, just once, someone will call me 'sir' without adding, 'you're making a scene." -Homer J. Simpson


My point is simply that what will come out of your personal pocket vs. the collective pocket is more a function of politics than technology.

I Think

that depends on

1. Your ability to take advantage of the federal and state tax credits (how much tax you actually pay that could be eliminated by the credit);

2. What you pay per KWH. If you're in idaho and enjoying hydro at 7 cents/KWH you'll never see the payback. If you're in California paying 25 cents/KWH (and above if you use over your "baseline" -what the nanny state thinks you should be consuming), and you can do a lot of the work yourself, the numbers might work out. Remember, you can always dismantle the installation and haul the pieces to Nicaragua :). Most US installations are going to be grid-tie, so you don't have batteries to worry about in the US.

3. If you are in Nicaragua and you know that your power cost will only continue to rise every year, and you would like an uninterrupted source of electricity.


4. Average daily sunlight hours in your region.


11c per kilowatt hour....

"Maybe, just once, someone will call me 'sir' without adding, 'you're making a scene." -Homer J. Simpson

I Read Once

that small scale solar would have to be part of the initial house design and construction before it took off in the US. Much like the HVAC. Or the built in appliances.

I can remember when most houses did NOT have central AC, and of those that did, many had massive natural gas refrigeration units because natural gas was so plentiful and demand (and price) was minimal during the summer.

There are some pluses and minuses to selling a house with a solar installation: Initial cost of the house is going to be higher by quite a bit, but the cost of the installation during construction is going to be significantly less than a retrofit. Much of this cost could be manipulated by mortgage incentive rates.

The relatively recent availability of natural gas will also affect the market. Smaller, more efficient, quieter gas turbines for converting the natural gas to electricity are being developed, with the German company Siemens leading the charge. These turbines have the added advantage of coming on-line and being shut down, quickly, in response to demand variations. So, they are a better fit with wind and PV than the traditional and massive coal fired generating plant. Because natural gas burns so cleanly the gas turbines can be placed closer to the users.

One of the advantages of capitalism is that resources are allocated by the 'invisible hand" (more accurately, the invisible hands of hundreds of lobbyists) so we all realize the most cost effective utilization of the resources available. While the process is full of aberration and anomalies I'm not sure that there is a better way. I have been disappointed by previous social experiments. Perhaps our ALBA friends will prove me wrong.

i really enjoy reading your stuff!

when i retire down there, I will buy the fdc if you will drink one or two with me!

"Maybe, just once, someone will call me 'sir' without adding, 'you're making a scene." -Homer J. Simpson