As a general ballpark idea, PV panels produce around 150-200 watts per square yard of land surface. A wind generator, for example, might produce 100 kilowatts while using around 250 square yards of land surface. The wind generator has the potential for producing more electricity from less property (but potential and actual performance are never the same). From the perspective of a land owner or rancher, the wind generator appears to be the better choice because most of the land remains usable for cattle or other purposes.
What I would like to know is exactly how much energy is being produced from the wind farms and at what cost in dollars. I have asked Xcel but I never received a straight answer. Of the few individuals that I spoke to who were installing the large wind generators, they said the profit was in the installation, not the energy output (but I have no means of verifying whether they told the truth or not).
On a normal panhandle property, a PV system will always produce more energy at a lower cost than a typical residential-sized wind generator. When including maintenance costs, residential PV systems are very inexpensive compared to wind. Residential wind generators suffer the problems of ice buildup, hail damage, lightening, and relatively frequent repairs. I have inspected the blades used in wind farms; the blades appear to have been constructed similar to the fiberglass forming methods used in aircraft, and my concern is their strength and resistance to panhandle hail. I personally would not live near a wind farm due to the noise, but some people seem to not mind. It is just my personal opinion, but I would prefer to see PV panels promoted for each family's roof and let the family decide how much energy they want to consume and pay for.
It would be very useful if someone could share actual costs and monthly output totals of wind farms. Without knowing the costs versus output, it is not possible to judge whether the wind farms are financially good, bad, or just a money-making opportunity for the installers.
You mentioned the footprint of wind generator towers. Is their a reason for PV systems to lay horizontal? Could they not also be verticle creating smaller footprints? I understand their would need to be spacing, but spacing is also necessary for the wind generators.
For the footprint idea, PVs need to face the sun as close to a 90 degree angle as possible so as to produce the maximum output. Running PVs vertical would produce electricity, but likely only maybe 10% or less of their rated output. In the winter, PVs are angled up towards the south to catch the south sun, and the PVs are laid flat (in my region) during summer to catch the straight-up sun. Kind of hard to do that with towers. ;-)
It is possible to install automatic aiming mounts to aim PVs on a tower towards the sun, but the expense is high, as would be the maintenance of always having to repair malfunctioning mounts. Installation costs can be cheap compared to the annual maintenance costs, which is one thing that concerns me about wind generators. I've made my living repairing electrical for almost 30 years, and when the decision is made for long-term costs, PV panels win hands-down.
The double-sided idea is interesting, but still there would be too large of a waste in materials and cost for what little electricity would be produced. From an investor's point of view, electricity is money, and the money is the one that decides that PV panels will be mounted horizontally.
Let's put this into perspective. The current plan is to spend something like 4 trillion dollars (which will surely increase in the near future) to install wind farms. The money for the wind farms will come out of your pocket and mine whether we like it or not, and we will continue having to pay for the wind farms forever and ever in electricity bills.
4 trillion dollars divided by approximately 150 million houses in the USA sums to about $26,666.00 per house (I do not know the exact number of houses in the USA, so my estimate is based on there being an average of around 2 people in each house more or less). The 'average' house can be retrofitted with solar heating, energy efficient appliances, and powered with solar energy for well under $20,000.00, and that includes paying a company to come out install everything.
It would be cheaper to give every home owner in the USA free solar water heaters, free PV panels, free new appliances, and free installation of everything rather than pay for the wind farms.
After the retrofit, the homeowner would have an annual maintenance cost of around $100.00 to $200.00, or perhaps less if the homeowner did the maintenance himself.
If solar energy was purchased instead of wind farms, the materials could all come from USA companies, be installed by USA companies, and maintained by USA companies. The installation of solar power would be a huge economic boom to the country and create hundreds of thousands of new jobs that would be permanent and with fairly paid wages. Too, the USA could be energy dependent within a few years, and forever remain that way.
Solar power is not being considered because there is no profit for the power companies. If solar power is used, it will not be to lower American dependence on foreign oil, but only to raise prices of electricity.
You are correct. If you watch the ads on TV, both wind and solar are shown in the plan. The idea is to offset the use of natural gas in turbine peak plants, primarily used to power air conditioners. That load can be 3 times the normal load and firing up peak plants is inefficient.
The 300 megawatt concentrated solar thermal electric plant at Kramer Junction in the California Mojave Desert has been operating for 30 years and provides lots of energy for southern California. They are expanding it to 1000 megawatts over the next few years so that the power companies can meet the 20% renewable mandate in the state.
About $250,000.00 more or less to power the average house with solar, plus a huge annual cost for maintenance.
But too, the average house consumes roughly 95 times more electricity than an energy efficient house.
People know that it costs more to fuel a 6 mpg Dodge truck than a 35 mpg Ford Focus, but the general public rarely gives a thought of the fuel wasted to run the average appliances. The average house could cut its energy consumption by 50-75% and more simply by choosing electrical appliances with better 'mileage'. If the concerned citizens of America would spend five minutes and learn how to figure wattage, maybe then they could make better decisions about what electrical devices to buy.
An 'average' refrigerator consumes roughly 3,000 watts daily, about $9.00 a month. Double-sided refrigerators often consume twice as much or more. An energy efficient refrigerator consumes about 240 watts daily at a cost of about .72 cents a month. The 'average' homeowner could not care less about how much energy is wasted.
There would not be a need for continued expansion of energy production if people would simply choose energy efficient appliances and learn what the "off" switch does. ;-)
For ease of estimating costs, let's round-off the cost of a 100 watt PV panel to be $700.00 each ($7.00 per watt including mounting). Subtract 10% efficiency loss from the wiring, subtract another 50% or more loss of power for cloudy days, subtract another 10 to 20% efficiency loss through inverters and batteries, and the 100 watt PV panel will provide the house about 35 watts per average sun-hour.
In a best-case scenario, 30,000 watt hours divided by 35 watts at 6 hours a day (210wh daily) equals 143 PV panels, not including storage batteries and other necessities. 143 times $700.00 sums to $100,100.00. Adding in enough batteries to power the house, and enough PVs to recharge the batteries, the cost easily hits the $250,000.00 mark.
I have seen solar and wind dealers claim that four to eight batteries can be recharged by a single PV panel, which is an incorrect claim. Storage batteries must have sufficient amperage to recharge; a tolerable minimum is 5 amps, which is about what a single 12v PV panel can produce. One PV per battery is minimal, with 2 PVs per battery preferred for recharging while the house continues drawing power.
If a storage battery costs about $200.00 and can dependably deliver about 20ah (240w), then about 125 batteries are needed for one day at 30kw, and 250 batteries for two days. The battery cost alone will be about $50,000.00, plus 2 PVs for each battery at 500 times $700.00 ($350,000.00), for a general total of $400,000.00.
Even if the $7.00 per watt estimate included purchasing PV panels wholesale at $3.50 per watt, the usable average output still remains at about 1/3, for a cost of about $10.00 per usable watt. 30,000wh in a region with 6 hours of good sun daily will still need about 5,000 watts per hour, which would then sum to the $50,000.00 estimate you gave, but the price does not include batteries nor the need for additional PVs to recharge the batteries. Adding in power surges for appliance motors, battery storage must be even larger.
Battery manufacturers provide spec sheets online that tell what amperages the batteries should be charged at. It is in the consumer's best interest to investigate the spec sheets before estimating the number of PV panels and wind power needed.
When we first estimate the battery storage needed, and then estimate the number of PV panels needed to charge the batteries, the actual costs are quite a bit different than what many solar and wind dealers claim. ;-)