Tags: solar, energy, power grid, subsidy
The Minnesota Legislature passed a law granting up to $500 million to fund solar power projects for Minnesota primary residences and businesses. Installers must be Minnesota businesses. Both thermal and electrical systems are eligible. If applications exceed $500 million, the grants will be decided by lottery. Grant limits vary by type of system and type of end user. Recipients will be reimbursed based upon the amount of electricity they generate in annual installments. Deadline for submissions is February 28, 2014.
A local church with a primary school asked me for an opinion. A State-qualified contractor proposed a $140,000 electrical solar panel installation. The following is my report, redacted to protect their privacy.
The proposal submitted by [contractor] describes a combination of a lottery, a public grant, a potential insurance problem, a potential cash-flow problem and a conditional sales contract. This should be brought before the Parish Finance Committee ASAP to assess the financial consequences of winning the lottery. The proposal also requires [Area Church] approval by [Area Church Insurer] before the Pastor could sign off on this lottery because it involves a conditional sales contract with [contractor].
As of today, the technology for solar energy is not competitive with other forms of energy, especially at this latitude. A year from now, that may change. A small company has a patent that [allegedly] coats the photovoltaic cells to double their efficiency. This startup company plans to build a manufacturing facility to apply coatings in a mass-production environment. This facility could be on-line within a year. However, their production will not handle the expected demand.
[Another neighborhood church] already committed to install a $140K solar array. You may want to talk to these folks since they are a block or so to your East.
Solar Power Infrastructure
Solar energy (photons) generates direct-current electricity when they strike the surface of a photovoltaic cell. Individual cells connected in series (called panels) multiply the voltage the same way flashlight batteries do when batteries are arranged head to tail. Banks of panels (called arrays) connected in parallel (one wire connects the heads; the other connects the tails), increase the amperage output that supplies a direct current (DC) load.
If the facility can use DC power, the arrays can be tuned to supply the voltage input of these devices. Otherwise, the DC power the arrays produce must be converted to alternating current (AC) before it can be used. These devices are called DC/AC inverters. If they supplement a total AC load provided by the local power company, the inverter must synchronize its output to match the frequency and precise timing of the local power company feed.
If there is a power outage from the array (night time) or a power outage from the power company, an automatic switch must be “locked and loaded” to disconnect the solar array instantly to avoid damage.
Electrical cabling is required to connect all of these components together. That stuff costs money too.
The angle of the sun varies up and down and side to side as the earth rotates. The solar array converts photon energy to electricity based upon the sine of the angle of the sun to the array. This requires actuators to focus the panels vertically and horizontally to face the sun’s rays to a 90 degree vertical and horizontal angle for maximum efficiency. That requires all-weather moving parts driven with electronics to point them at the right place. That extra feature also requires maintenance and more money for maximum efficiency.
Today’s solar cells reflect about half of the sunlight they receive. A startup company has a patent and demonstrated a proven method to coat solar cells so they absorb all energy instead of just half. However, the coatings must be applied only to uninstalled panels under clean-room conditions. They are building a coating plant to mass-produce coated panels. When it comes online, there is no way it will meet market demand. Read that expensive, even if customers wait until this technology is available.
Solar panels do not work as advertised if they are covered with dust or snow, or succumb to hail damage. Dusty wind, airplane engine fallout, automobile exhaust and diesel particulate exhaust coat the panels with sticky goo. Abrasion and chemical corrosion attack the surface of the solar panels. That combination diminishes their serviceable life. Ergo, these panels do not last forever. Some installations in semi-desert areas even protect their solar arrays with glass housing similar to growers of plants and flowers.
If the solar array is roof-mounted, how does one re-shingle a roof or repair a leak? If it is a flat roof, these roofs are born to leak. Every hole is a potential leakage spot. Arrays require lots of footings. Will the solar arrays require lightning protection? How about electrical grounds?
Also, someone has to remove the dust, snow, and sticky goo. The actuators, inverter, fittings, and other stuff need periodic maintenance.
And then there is the matter of insurance premium expense to cover an extra $140K+ increase in property value.
[Local Church and School] Solar
The lower-school has a flat roof over the auditorium. This is enough space to support a large solar array. The electric transformer that powers the entire campus is located outside the south side of the school next to the gymnasium entrance. The inside of that outer wall is backstage of the auditorium. That area provides a straight shot directly to the area above the auditorium with no barriers below the flat roof. This looks to me like a very simple and straightforward installation for a connection between a roof-top photovoltaic array and the central power source for the entire campus: the load side of the power company’s three-phase transformer.
The middle school [connected but separate building] also has a flat roof, but it has a roof-mounted air conditioner in the way. It could support a solar-thermal system that could heat water. The interstitial space behind the middle-school bathrooms provides a straight shot through unused steam pipe chase holes through the floors from roof to the crawl space under the first floor.
The foyer roof is flat, but unsuitable for solar. It is lower than the other buildings. That would restrict sunlight. There is no direct connection for either electricity or hot water.
The lower school roof is the best choice.
Total Cost of Ownership
Assuming [local church and school] gets a grant for $140K, what does it buy and when do they pay? So far we identified a lot more stuff than a solar array that is required to make this work. We also identified more ongoing costs to own and use after it does work. If Shakespeare was a member of our finance committee, he might say, “Methinks the devil is lying somewhere in the details like a lion ready to pounce.” Perhaps we need to “peel the onion” and take a closer look.
The Political Factor
What and who is driving this lottery? More important, why are they doing it?
[Electrical power company] and the other regional electric power providers have a new franchise agreement. Among other things, it includes a mandate that the power company’s generation capacity must include at least 20 percent renewable energy.
These power companies have some options to consider. Some people call these options “tough choices.” This is management language that means “It does not make economic sense, but we have to do it or lose our franchise.”
One way to do this is to buy renewable energy from someone else. Power companies can buy surplus renewable energy from consumers (even if they don’t buy much). If they do, the power companies can count the consumer’s capacity as part of their renewable energy capacity. Ergo, they do not have to finance the renewable infrastructure or maintain it. The capacity they buy comes from their customers who are at the consumer end of the wire, not the power plant’s end of the wire. This means that they do not have to endure the power loss and and invest in the distribution infrastructure to transmit as much electricity from point A to point B, C, D and E.
What is the worst condition power companies face (not including Christmas lights)? It is hot summer days during the work week with air conditioners on full load with no wind.
Conventional steam plants require up to 18 hours to reach their full generating capacity. They run most efficiently at full load. They cannot respond quickly to peak load. The power companies need natural-gas-fired turbines (jet engines connected to dynamos) to handle peak loads. Jet turbines need only a few minutes to handle the peak load that stresses their generation capacity. Also, they can be throttled back to partial load conditions quickly. Natural gas is NOT a renewable energy. Even though power companies do not run gas turbines all the time, their full capacity is part of total non-renewable generating capacity.
If wind farms have no wind, their output is zero. Yet their full-load capacity is used to determine the power company’s total capacity for renewable energy.
If the winner is a for-profit corporation, the property taxes increase because the solar array system increases the assessed property value. This benefits the tax jurisdictions (school district, city, and county) for the life of the installation. Heck of a deal for whom?
The surest way to make the new system cost more than the old is to pioneer the wrong thing. The surest way to lose in poker or blow a budget is to throw good money after bad, trying to make the wrong thing work. The surest way to make a solution fail is to let a politician design it.
Tags: solar, energy, power grid, subsidy