Remote Power, Communication, and Living Systems

Home ] Email PS ]

Up ]

PV (Photo-Voltaic) Solar Electricity

On the grid, or off, PV (photovoltaic) panels can generate electricity for you.

Solar can also be used for solar water heating.

The batteries enable you to have power at night (when the sun isn't shining), and on cloudy, rainy days.  The solar panels re-charge the batteries.  To ensure you don't over-charge the batteries, there is a charge controller that regulates the power from the PV panels before it gets to the batteries.

An  inverter converts 24 VDC to 110 VAC household power.

This system supplies summer power to a remote camp.

The basic equipment is approx. $4,000 to purchase.

System prices usually range from $400 to $15,000 depending on your needs and system capacity.

The picture above shows a small solar PV system which has one 165 watt and two 75 watt panels, for a total of 215 watts.  Generally, PV solar panels sell for $5/watt at 2007 prices.

There are 1,000 amp-hrs of  batteries, a 1500 watt inverter, and a 60 amp charge controller in the boxes behind the PV panels (on the raised platform).

The vertical pole to the left is the base for a 400 watt wind turbine.

Pioneer Systems is experienced in assessing your site for the amount of sun availability. 

Sometimes trees, hills, and other buildings may block the sun at certain times of the day, or at some seasons during the year.

Some dealers will sell you a "too small" system, or inferior quality, getting the attention of the unaware prospect with the cheapest price.

Unfortunately, the unaware homeowner might be comparing apples to oranges when they make their initial decision.  Experience over many years may re-educate these consumers.  These dealers realize once they get the first sale, that initial customer will probably buy more from them in the future when they want more power, or the initial system fails.  Unfortunately, it is always more expensive to upgrade/replace than get it right in the first place.

Some dealers will sell you too big of a system (or one with many bells and whistles) because they can make more profit off you. These consumers are usually very happy with their system, until they realize how much more they paid than others.  In this case, the unwary consumer pays too much for a system capacity (or bells & whistles) that you will rarely (if ever) use.

For example, rather than investigating wind power, many dealers sell double the number of solar panels, and double the size of the battery bank.

I live off the grid with a hybrid wind and solar system.  I've gone out on cold, dreary winter days and been shocked at how little power my PV solar panels generate.  During the winter, the sun only generates 37% of the power that occurs during the summer (with 100% clear skies).  Add to that a day with heavy overcast, and we get 1% to 3% PV power compared to full summer sun on a clear day.  If the PV side only generates at 3%, why would you want twice as many panels for an ineffective solution?  Thank goodness I also have a wind turbine.  When it is overcast in the cold winter, it also tends to be more windy than usual.  That is when it is cheaper to invest in wind power (if your site is suitable), rather than doubling up on PV panels and batteries.

Pioneer Systems knows what works, and can recommend how best to invest in green power, helping you achieve your goals.










This diagram shows data we collected at one person's house.  The compass points us due South.  Going left to right in a series of arcs, we see the time of day, from 6:00 AM to 6:00 PM.  The series of arcs are for the sun's position for different months of the year.

The yellow line shows where the shade will be during winter (deciduous trees inside this block about 50%, outside that is blocked almost 100% year round).

Based on this information, we can design the exact system you need:  not too big, not too small, just right for your site and needs.

Pioneer Systems, working hand-in-hand with you will tell you the available choices, what to look out for, and do all the design work to get the right system for your needs.

Once the system is designed, Pioneer Systems can buy the equipment, install, and service it so it stays working and reliable for its entire expected life.

Outback Inverters are designed to take either 12, 24, 36, or 48 Volts DC as input, then convert it to 110 V or 110/220 V AC household power.

This electrical conversion from DC to AC is done at ~90% efficiency.

Outback inverters also include a charger.  The charger takes AC power in (from the grid or a backup generator), and rectifies it to DC so that you can charge your batteries.  This is useful when you have a small, continuous need for power, but don't want to keep a noisy, expensive, polluting backup generator running 24/7/365 to power that small, continuous load.

Possible Uses for Solar PV

  • Off-grid house, cottage, or camp
  • On-grid green energy to reduce your peak consumption and average use.
  • Back-up power for when the electrical grid goes down
  • Emergency power during storms and natural disaster
  • Power for remote sites, cheaper than an additional electrical grid meter or running an underground line.
  • You need DC power, and direct generation by PV is cheaper/better than rectifying AC to DC
Magnum and Xantrex (Trace) are other brand names of inverter/chargers that are well respected in the industry.

Like Outback, Magnum can have a remote display, command, & control panel, automatic generator start, an E-panel for all the AC and DC breakers, and act as a base for attaching auxiliary equipment like charge controllers, lightning arrestors, etc.

Let Pioneer Systems design a system for you.

During the last few years, there are some new suppliers from China.  Based upon Pioneer Systems' research, all that we have investigated have very low prices, but the reliability and ruggedness of their product leaves much to be desired.  Many have had the bitter experience of a total system failures, rather than the expected 10 to 20 year life they invested in.  At this time, Pioneer Systems does not offer any of these cheap, but disappointing technologies.

Is PV Solar Green Power ?

Most people think it is.

Grid electricity is generally produced by converting coal, oil, natural gas, or nuclear to heat and electricity.  Unfortunately, 60% comes off as heat that is wasted (ejected into a river, lake, or the atmosphere), and only 40% gets turned into usable electricity.

The transformers, switchgear, and wires between the generating plant and your house will eat up 9% to 15% more of the power.  Check your utility bill, because in spite of this loss being on the utility's side of your house's power meter, you get stuck with the bill for these losses as well.

In total, we use 100% of the fuel's energy, get 100% of the pollution, but only get 30% of that energy delivered to your home for use.  Adding in administration charges, taxes, and debt retirement, you end up paying approximately $0.155 per kW-hr.

With PV solar, about 15% of the sun's photons get changed into electrons, but once converted they are 100% useable.

If you have batteries, they are 90% efficient.  10% is lost by the chemical conversion charging & discharging inside the battery cells.

If you have an inverter to change from DC to AC, the modern ones are about 90% efficient.

The worst case PV system with batteries and inverter will be 81% efficient with the electricity generated; more than double that from the grid and your bureaucratic utility company.


Top of Pole mount for 2 PV solar panels.

Ground mount for 4 PV solar panels.  If you want power in the winter, be sure to leave at least 3 ft. for snow sliding off the panels and drifting in front.

Roof top mount can be adjusted for any flat or sloped roof, asphalt shingles, steel, or cedar shingle/shake.  They can be aluminum, steel, or hot dip aluminum-galvanized steel with a 40 year galvalume coating life.

Batteries are the heart of most PV solar system.  If you have (or want) batteries, generally you should invest 30% to 50% of your total system cost into batteries.

Some batteries can do 50 charge/discharge cycles (eg. vehicle starting batteries) or 3 months life.  Other battery types are good for 5,000 cycles and 20 years in solar service.

How do you find out what's the best battery for you?  What most people are looking for is the lowest cost $/amp-hr over the battery's expected life.

Talk to Pioneer System.  They have the answers you need.

2001-2009   Pioneer Systems   All rights reserved.  All other material owned by their respective copyright holders
Page Last Modified:   04-May-2009 05:45:36 PM -0500