Interesting read- short sweet and to point!

http://www.popsci.com/article/science/americas-rooftop-solar-panels-are-probably-facing-wrong-direction?dom=PSC&loc=poprail&lnk=4&con=americas-rooftop-solar-panels-are-probably-facing-the-wrong-direction

Also read that solar panels are not sustainable at all because they require more energy to make in form of oil than they produce in their lifespan in the form of electricity.

What think you all?

I didn't read the article, but .......... Quite frankly, there's not much about our lives that is truly sustainable. The human race is gobbling up this planet's resources at an incredible rate. The only way to live a truly sustainable life is to drastically change our lifestyles, something that just won't happen until civilization collapses and the world's population plummets.

M.R.J. Smith wrote:
Also read that solar panels are not sustainable at all because they require more energy to make in form of oil than they produce in their lifespan in the form of electricity.

I have read that before. I'm not aware of any source of electrical energy that is "sustainable." Does the article suggest a sustainable source? If not, we need to focus on comparing the ones that exist.

Bill Mollison has talked about Tromps but I don't think that was for electrical energy and right now we can't purchase one.

Does the article suggest that nukes are more sustainable because Fukushima & Chernobyl would suggest otherwise - they don't generally include the embodied energy of the plants themselves, or the possibility of quarantining a radioactive site for say 50,000 years.

In a weak moment, I checked out the article and it wasn't what I thought.

While south-facing solar panels are the most profitable for panel owners, they actually raise the demand for other power sources that they simultaneously put out of business. Relying on morning and evening sunlight means that solar panels aren’t producing as much as they could during the middle of the day, when communities need the bulk of their power. Therefore, homes with solar panels continue to rely on other power sources to support them during the middle of the day.

The article is making an awful lot of assumptions. It assumes no trackers are used, that the house is connected to the grid, that the grid relies on natural gas.

Solar energy is under attack at the moment because it has reached a price point that is going to threaten the current utility system. Price per watt is under a dollar and in bulk under .50 cents and FALLING.

The article contains a bunch of half truths and twists them to make the problem seem to be caused by solar but it isn't. Okay, get ready for a long winded explanation by someone who made a living working for a number of the major residential solar installers.

Electricity costs more during the day than at night. Nighttime energy is the base load, it is generated by the cheapest and most efficient producers but most of those can only increase their output marginally. During the day, especially during high demand summers with A/c running, utilities need to bring more expensive plants online to generate energy and that is called peak load. Most utilites don't sell homeowners electicty based on "time of use" they do it by volume so the cost difference between day and night energy is not passed on accurately to consumers. This cost difference in California is significant enough PG&E pumps water UPHILL during the night in a number of places using cheap night time baseload energy so that they can run that same water downhill during peak demand and generate far more expensive peak load energy.

The article skirts around that fact. So what it isn't saying is the current billing systems usually treat all electricity as equal so you get a 1 to 1 swap even if you were generating the most valuable peak load energy in the afternoon and getting cheap night time base load in return. So for a homeowner the most effective orientation is one that generates the most power regardless of timing. This is ALSO why utilities are afraid of time of use net metering. Already the point at which residential solar will start affecting their profits is on the horizon but combine the massive price drops with THIS concept:

IF homeowners COULD get the value of their solar during PEAK demand and take it for CHEAP base load at night the trade would go from 1 to 1 but 1 to 3 or so!

Forget the fact that would make FAR more sense to the nation or the environment, or a host of things, it scares the begezus out of their beancounters! In places like California electricity is sold to consumers in tiers, use a little you get a subsidized rate which is offset by the higher rates paid by users with bigger homes, more pools and thus have higher usage. Who does solar make the most economic sense to? Those high volume users who subsidize the lower rate tiers. So what they are facing is raising the lower tiers because people with higher bills are the easy market for solar but as they raise their rates that makes new candidates for solar and they can see the looming problem to their bottom line and are now paying to have ariticles like the one above published.

As an aside, solar makes a ton of sense in California and other states with electrical rates above .15 cents, many states still have cheap power and it makes less sense unless you are never moving but as the cost falls that will change.

Cj et all : The State of California is now trying to encourage most D.I.Y. /
retro-fitters of solar panels to face at least some of panels more to the west,

The goal here is to have the 'Solar Panels' cranking out maximum Ergs of energy
simultaneously with the evening high crest in energy usage when everyone comes
home at the same time and starts using power !

For the Craft! Big AL

Yes, Al, the article actually wasn't slamming solar, just that orientation of the panels wasn't best for the overall good. Pretty big distinction.

Agreed. Where exactly did the "more energy to make..than they produce" come from.? This would only be true if they were never put into service or had a an unrealistically short life.

PV is now cost competitive with fossil fuels in many situations and is transforming the utility and distribution industry. Investing in them and facing south or west is great for the environment, especially when tied to the grid. Hopefully the storage issues will make the same strides as PV has. There is lots of promising development in this area and I think the future is bright.

It is also important that consumers of solar PV can get the best return on their investment which lowers the cost per Kwh. The lower the cost per Kwh, the more people will install solar panels, and the more people install solar panels, the more the costs come down for the industry. It is one big virtuous cycle.

Regarding the sustainability of solar panels, the current crystalline silicon modules are quite energy intensive to produce, but researchers are hard at work developing next-generation polymer and organic solar cells that would require much less energy to produce as well as be cheaper.

Something to look forward to

It's important to use the latest data, as manufacturing keeps getting more efficient. Sundug
=======================================

Sometimes renewable energy skeptics question how much energy it takes to produce and ship a solar panel in comparison to how much energy the solar panel will produce. If, for example, it took more energy to manufacture the panel than the panel would every produce in its lifetime, it would not be reducing the carbon footprint it was designed to offset.

However, new studies are showing that it takes less than 3 years for one solar panel to offset its “embodied energy.” After that, all the energy that the panel produces is completely clean and does not need to be accounted for in any manufacturing processes or raw materials used to make the panel.

One study concludes, “Unlike conventional energy sources, PV systems produce clean electricity for decades after achieving their energy payback in three or fewer years—this is truly the magic of PV technology.”
Read the full studies here:

PV Embodied Energy from Home Power Magazine

PV Embodied Energy from Energy & Environmental Economics

http://www.renewableenergyworld.com/rea/blog/post/2011/07/studies-show-pv-panels-return-embodied-energy-in-1-3-years

While south-facing solar panels are the most profitable for panel owners, they actually raise the demand for other power sources that they simultaneously put out of business.

What a load of horse shit. Raising demand drives prices higher, not lower. If there is any truth to this it is due to uneconomic government regulations on the power plants, not due to use of solar. If those panels were not on those roofs, the people would still be using utility power mornings and evenings.

If peak electricity costs more, then utilities should price it higher. My wife had a business in Wyoming that paid partially for kwh and partially for peak load, so they certainly can do it - if the government gets out of their way.

Also, it's a bit of a stretch saying that movement from nuclear to gas utility power is worse for the environment.

The most sustainable fact about localy produced electric energy is the fact that you will spend your energy with a lot of care, and do everything you can to reduce energy consumption. Next, if grid fails, your system still works, so your meat will stay cool in the fridge. Next, you can build your house anywhere, you don't have to look for site near common infrastructure. This means that you can inhabit much more acceptable place for living, not just following someone else decision. And with your own energy source you are "movable". Humans were living as hunters-gatherers for most of their (pre)history, and during that time they were mainly nomads. I must assume that nomadic way of life is most, if not the only sustainable way of life for people. PV panels are giving you back that movability.

Grid intertie has several advantages, it`s cheaper, simpler, greener than stand alone PV. I know personally 7 off grid households, they all have run thru several sets of expensive, toxic, heavy batteries, they all use dirty, noisy, PIA backup generators for the cloudy periods we get, they all only get 80-85% of the energy they put into batteries back from them, they all fill their battery banks when they have two sunny days in a row, then any more solar energy produced is wasted. With a grid intertied PV system, 100% of any electricity that you produce but don`t need immediately, goes into the grid, in the seven states TVA serves, I get paid 12 cents a KWH MORE than TVA charges. This way your neighbors can use your excess solar electricity, and you get a credit, if you run a surplus you get a check. http://www.tva.com/greenpowerswitch/partners/
=====================================
My grid tied 4.6KW system produces more than my home uses, so we have no electric bills, 100% of the Green energy it produces gets used, and I get paid about $800 a year for the clean energy I put into the grid for my neighbors to use, displacing the carbon based energy they would of burned.
http://www.builditsolar.com/Projects/PV/DougEnphase/DougEnphase.htm
https://enlighten.enphaseenergy.com/public/systems/dpBj53033
=======================================================

http://www.txses.org/PVgrid.php
One increasingly popular way of using photovoltaics is what is known as "grid-attach". In this configuration, the consumer stays attached to the electric company (the "grid"). The PV system forces whatever it produces directly into the building's AC lines. If the PV system is producing more than the building uses, the meter runs backwards. If the building is using more than the PV system is producing, the difference is made up by energy from the electric company.

This type of attachment has a number of advantages:

It is cheaper, because there is no need for batteries.
It needs less maintenance, again because of the lack of batteries.
It makes the most effective possible use of the energy that the PV generates: because the grid is always able to accept any surplus, the PV panels can always be operated at their most efficient point.
A Utility Intertie System Without Batteries

This is the simplest and most cost effective way to connect PV modules to regular utility power.

All incoming PV-generated electrons are converted to household AC power by the intertie inverter and delivered to the main household circuit breaker panel, where they displace an equal number of utility-generated electrons. That’s power you didn’t have to buy from the utility company. If the incoming PV power exceeds what your house can use at the moment, the excess electrons will be forced out through your electric meter, turning it backward. If the PVpower is insufficient, that shortfall is automatically and seamlessly made up by utility power.

Have you considered going completely energy independent with a solar power system? That is, do you long for going off-grid, free from the expensive rates of utility companies? I had always thought that off-grid was clearly the way to go, until I did a bit more research.

There are a number of pros and cons for you to consider when implementing a solar power system that will take you off-grid. First, let’s review the three types of solar power systems:

On-Grid Battery Solar Power System
On-Grid Solar Power System without Battery
Off-Grid Solar Power System
With an on-grid battery system, a back-up battery is included as part of the solar power system. Batteries can store excess energy generated by the solar panels, and even send the surplus electricity out to the grid. Of course, the system is connected to the electricity grid which is why it is called “on-grid.” The solar panel system includes solar panels, a charge controller, battery, inverter, AC service entrance and AC subpanel, and a utility meter.

You can still stay on-grid without a battery, however. These solar power systems are the simplest and least expensive to set up. All that is included is the PV array, an inverter, AC service entrance and utility meter. Your system is connected to the grid, but there is no battery back-up. The obvious drawback is that when power goes out in your area, your solar power system will also shut down.

Finally, there is the off-grid solar power system. There is no tie-in to the electricity grid. Batteries are required as part of the system in order to store excess energy.

Turning to a comparison of on-grid vs. off-grid solar power systems, there are clear advantages and disadvantages to each of these.

Off-grid systems are the only way to go if you live in a remote area where there are no utilities. In fact, you can get a better deal on rural properties that are not connected to the grid because of the expense of running lines out to the home.

But, if you have the ability to connect to the grid, why wouldn’t you? First and foremost is the idea of independence from utilities. No more worries about rate increases. If the power goes out, your lights and refrigerator (and television and radio) are not affected. Second, due to the cost of an off-grid system, many homeowners find themselves forced to conserve energy rather than expand the system to generate more power. This is very appealing to the environmentally-minded.

What are the down-sides for going off-grid? Instead of the utility company maintaining your system, you’ll be doing it all yourself. Batteries will have to be replaced (about every 5-15 years) at a cost of at least $1000. In addition to the cost of the batteries is the inefficiency, which increases as the batteries age. They start out at about 90% efficiency. Moreover, when you’re not connected to the grid, excess energy that is generated is not fed out to the utility to give you an energy credit (this can happen with on-grid systems). Off-grid systems must use the surplus or lose it. Finally, most off-grid systems include a back-up generator, which can be very expensive.

For an on-grid system, the primary upside over off-grid is that you can draw on grid-based electricity when necessary, rather than either go without power, or use a fossil-fuel based generator. You still get a great deal of independence and cheap electricity, but it may be more reliable in many ways.

The biggest question for you is whether you will include a battery or not. Battery-based on-grid systems cost about 35-50% more than without, but you lose the opportunity for back-up without a battery. Also consider the cost of utility line extension for grid-ties. If you are close to the line, it may cost you nothing. But if it will be a major extension, it could be very expensive and you may decide that staying off-grid is the best way to go for your home. If you tie into the grid, be sure you are clear about the question of net metering (when you can sell back excess energy to the grid for credit).

Fortunately, there are many solar power system options for homeowners. No matter your circumstance or where you live, you can find a way to use solar energy to power your life!

Library of State-Specific Interconnection and Net-metering documents-
http://www.irecusa.org/index.php?id=30



If money were no object, I’d opt for a grid-tied system with batteries. While such a system provides the best of both worlds, it is also the most costly. A grid-tied system with batteries must be able to automatically disconnect from the electrical grid when the power fails. If not, it could be dangerous for utility workers in the area. As a major advantage of such a system, it uses all of the free-power available, only switching to costly grid-supplied power as a last resort. Switching is automatic, based on setup parameters. The system can be set to be very gentle on the batteries, extending their life, or be set to use them to a greater extent, resulting in a lower electric bill. It must be great to have choices like that!

I think it’s reasonable to assume that while grid reliability problems may increase in the future, the grid is never going to disappear completely. As long as it is there part of the time, those attached can take from it and contribute to it. And those who supply power to the grid are paid, or at least credited, for their contributions. So unless electric rates or grid-connection charges are prohibitively high, being grid-tied makes more sense from a financial standpoint than an off-grid system does. And since an off-grid system with batteries efficiently uses the energy generated by the sun, it’s a good “green” choice.

While a batteryless grid-tied system is efficient and cost-effective, it must be embarrassing to have a large PV array, but no power when the grid goes down. What would the neighbors think? Still, this type of system is the best “green” choice, and it requires the least maintenance.

Efficiency – When your batteries are full, they’re full. No matter how hard the wind blows or the sun shines, you can’t harvest anything more. A grid connection allows you to harvest all the power from your system. When you have extra, you sell it to the grid so someone else can use it. When sun or wind is scarce, you tap in and buy some back.

Cost - Solar equipment is expensive. You can run a few lights with a car battery, but if you’re serious about powering your home you’ll probably want a set of good-quality deep-cycle batteries. These can set you back $300-$1,500 apiece. You can expect to have to replace them about every 7 years – maybe longer with good care. If you have batteries you’ll also need a charge controller – another $150-$600 or more. Connecting to the grid allows you to dispense with batteries altogether if you choose.

Convenience – Off-grid systems require constant monitoring. Flooded lead-acid batteries are long-lived and cost-effective, but they need frequent maintenance. Living off-grid also requires you to adjust your energy consumption according to available power. If you have a few days without much sun or wind, you may have to ration your power use or supplement with a generator.

Self-reliance – No doubt about it, when you’re off-grid you’re not at the mercy of the power lines. There is something to be said for being able to offer your neighbors water, for instance, after a tornado goes through and they have no power to their pumps.

Politics – You may have strong feelings about your power company. You’re entitled to them; just don’t let them act against your own best interests.

Ask nearly any PV installer, and they’ll tell you it makes sense to connect to the grid. But at the end of the day, it’s a decision you need to make for yourself. And don’t forget – it’s not an either-or decision. You can grid-connect and have an emergency battery back-up, too – the best of both worlds!



With grid tie and battery backup, you will take about a 10% hit on overall
efficiency of your system. That being said, it is still about 20% more
efficient then an off grid systems where you are drawing off the battery
every day and having to recharge them. Batteries are only about 80%
efficient meaning you have to put 20% more energy into them then you can
take out.

Outback is a very good brand for this. the thing to know tho, is that the inverter is complicated and more expensive if it charges batteries too. That means that when the batteries are full, the inverters efficiency is still lower because of it's use as a charger, your not getting the full benefit of a grid tied inverter, it's less efficient.

Doug Kalmer wrote:I know personally 7 off grid households, they all have run thru several sets of expensive, toxic, heavy batteries, they all use dirty, noisy, PIA backup generators for the cloudy periods we get, they all only get 80-85% of the energy they put into batteries back from them, they all fill their battery banks when they have two sunny days in a row, then any more solar energy produced is wasted.

The energy doesn't have to get wasted. It can be shunted off to something like an electric hot water heater and put to use.

Ironically, the original article the OP linked to had a similar issue with grid-tied solar panels. It was something like everybody faces their panels south when that energy is needed least and it would be better for everyone involved (except the person putting the power in to the grid) to have those panels face west.

I'm not sure how the grid shunts excess power. Off-shore wind systems are not too practical because there isn't a great way, yet, to store that energy.

True, but its an exciting time of development and we may be seeing the horizon in the new technologies that will make it possible. PV + Grid is already doing wonders. Add in grid storage and we might actually be looking at a grid on the road to sustainability. Potential off-gridders in reach of the grid: We need yo power!

Seems like there is another alternative: batteryless grid-tied with a generator. Comparing this to a battery grid tie, you are storing energy in gasoline rather than in battery plates. Gasoline storage is very cheap! You cannot get more gasoline from your panels (like you can get power in an off-grid system), but at least you can run your freezer a couple times a day when the grid goes down...

The idea that it takes more energy to make a panel than you will ever recover from that panel -was- true. In about 1950.

But ever since then, it's not true. Not true. Really really not true. And it has been studied extensively.

And, as panel technology continues to evolve and improve, it will get less true all the time.

While not a conspiracy theorist, it does strike me as odd that this now false factoid just will not go away. I wonder who would benefit from casting doubts on the efficiency and sustainability of solar pv...?


Yes, solar panels cause some change/harm to the environment.

Hey, how 'bout that coal mining???


Hey, how 'bout all those wars in the middle east that have something, overtly or covertly, to do with oil? How expensive and sustainable is war for oil?


Hey, how 'bout that enriched uranium that produces waste products that have to be safely stored for like 100,000 years, how's that working out???




So, as one can see, all electricity comes at a price to the environment. Our job as stewards is to find the least damaging way and improve that.



troy