Friday, June 20, 2014

The Future of Photovoltaics

(Updated from The New Solar Electric Home - The Complete Guide to Photovoltaics for Your Home, 3rd Edition, 2008, by Joel Davidson and Fran Orner with our sincere thanks to Christina Bych)

PV has evolved from a scientific curiosity to a reliable power source for orbiting satellites and space stations to cost-effective power for remote homes and villages and to renewable energy distributed generation in cities and towns around the world. PV use will continue to rise rapidly as the need to replace fossil fuel and nuclear power plants becomes increasingly critical. The change to PV will accelerate as new materials and production methods come on-line. As more people understand how easy, practical and rewarding it is to use PV, electric utilities will find ways to integrate privately owned PV into the grid power mix. PV is already becoming an important addition to utility companies’ portfolios.

Building Integrated PV (BIPV) will become commonplace. Today, megawatts of PV roofs, curtain walls and power generating windows are being built. PV shade structures and carports are turning parking lots into solar power plants. Tomorrow, BIPV and PV shade structures, which are simply PV arrays with long legs, will be deployed on polluted urban wasteland as part of the “brownfields” cleanup process.

In the not-to-distant future - less than 10 years if we focus our resources on peace and plenty instead of war and waste - buildings will be rated either net energy consumers or producers. Older, high density, multi-story buildings like skyscrapers and inner-city hospitals with limited roof space or inadequate solar access will continue to be net energy consumers while new buildings will be designed to produce all the energy they consume. Low energy use buildings like warehouses will have PV roofs that produce excess electricity for sale for credit or directly to their neighbors.

Homes in the future will be super energy efficient and have PV roofs to provide all the home’s electricity plus power for the homeowner’s electric (EV) or hydrogen fuel cell automobile. PV modules are already available in many shapes, sizes and colors to fit any building application. Mounting hardware is already more user-friendly. Building-integrated mounting and wiring will be inconspicuous. Multi-purpose inverters that operate with or without batteries will allow you to choose battery backup now, later, or not at all and back-up power will be stored as hydrogen and utilized through fuel cells. PV on home, garages and carports will charge EVs and solar power stored in EV batteries will be fed back into the utility grid to reduce the need for polluting, inefficient fossil fuel peaker plants.

Electric service panels will be made solar-ready with built-in connections and circuit breakers for on-site power production. Electricians and tradespeople are learning how to install PV just as they learned to install heating and air condition units a few decades ago. Someday all electricians will be as familiar with PV as they are with lighting equipment.

PV will change the way people think about energy production. Most of us are already concerned about continuously increasing consumption, power plant pollution, diminishing energy resources and buying oil and gas from nations that harbor terrorists. On-site PV equipment costs are now included in homeowner’s mortgage payments in lieu of paying a separate monthly electric bill. Mortgage-financed PV is already cheaper in many places than utility power. In Asia, Europe and the United States every year hundreds of thousands of people buy PV for their homes, schools and businesses for economic and environmental reasons. This trend is expanding throughout the world.

In the future, politicians will be required to provide energy solutions that reduce the threat of war, improve the environment, and enhance individual freedom.  Individuals and corporations will be held responsible for the energy resources they consume and the health and environmental impacts of their actions. PV will help everyone to meet these goals.

On-site PV use will grow by thousands of megawatts every year. Large-scale centralized PV power plants will still be required to power urban areas that house over 50% of world population, but plans are on the drawing board for a global network of PV arrays that will feed into a global electric grid. The Genesis Project is one such plan. Genesis, which stands for Global Energy Network Equipped with Solar cells and International Superconductor grids, is the brainchild of Dr. Yukinori Kuwano, one PV’s most innovative scientists and founder of Sanyo’s PV division. His 200-year plan is to make PV the planet’s prime energy source. (1)

The Genesis Project is not science fiction. A look at Earth from space shows that rainy and cloudy areas cover less than 30% of the total land mass and that it is always daylight on one side of the globe. A global PV power grid connected by super-conducting cables would enable daylight areas to provide clean solar energy around-the-clock. Super-conducting cables are practical today and plans are to increase their use. (2)

When Dr. Kuwano first proposed the Genesis Project, global energy demands were the equivalent of 14 billion barrels of crude oil per year. About 4% of the world's desert area (800 km square) covered with 10% efficient solar cells could meet this requirement.

Is a global PV grid possible? People who install PV power generation systems on their grid-connected homes and businesses are building the global PV network right now. As this trend grows, national networks will then be connected by superconductor cables now in development.

The United States, Canada and parts of Mexico are already interconnected as are the electric power grids of some European countries. The "Silk Road Genesis,” proposed by the Tokyu Construction Company, calls for the construction of PV power plants along that ancient trade route. The first stage of the project, which now includes the support of Sanyo and other companies, involves building over a hundred 100-megawatt PV plants along the Silk Road by 2030.

Desertec is another large scale project aimed at creating a global renewable energy plan based on the concept of harnessing sustainable power from sites where renewable sources of energy are more abundant and transferring it through high-voltage direct current transmission to consumption centers in north Africa and Europe. All kinds of renewable energy sources are envisioned, but the sun-rich deserts of the world play a special role. (3)

Even if it takes 50 years for a global electric grid to materialize, hundreds of megawatts of PV are already connected to local and regional grids while hundreds of thousands of households in developing countries are getting their first electricity from PV each year.

While you were reading this short chapter, more than 300 kilowatts or about 30,000 square feet of PV were installed. In 2013, over 4,220,000 watts (4.22 megawatts) of PV were installed every hour (4). We hope you will join the PV Revolution and go solar now.
(1) Genesis Project
(2) Super-conducting power cables
(3) Desertec

(4) 2013 solar installs hit 37GW

Monday, June 16, 2014

Early Solar Powered Computers

August 1999, I asked some hands-on PV pioneers who had the first photovoltaic powered personal computer (PV powered PC). Here are their responses and some comments.

My own PV powered PC experience began July 1982. While living in the Arkansas Ozark mountains, I got an Apple II Plus. I wanted to connect the computer directly to home 12-volt DC PV system instead of using an inverter so I called Apple Tech Support to make sure what I wanted to do would not harm the computer. Apple technicians told me that my computer was the first PC they knew of that was PV powered. I connected my 12-volt PV system battery bank (6 each 2-volt 400 amp-hour C&D lead-acid cells) to a separate 12-volt group of gel cells. The gel cell 12-volt output was connected directly to the Apple’s hard drive and the computer's 5-volt RAM was connected through a voltage-dropping resistor.

When I moved to Los Angeles in 1982, I continued to power my Apple II with PV using a Tripplite 550 inverter with a 120-volt square wave output. I have also owned Compaq, Kaypro, IBM and PC clones that I powered with Tripplite, Heart and Trace inverters. Most PC power supplies can work with unfiltered utility power so they could also work with most of the square and stepped square wave inverters available back then. I also powered my Sharp laptop and Epson notebook with PV power and a voltage dropping resistor into the internal battery. Computers and PV power are very compatible. This blog was written on a desktop PC in a completely solar powered home and office. See

Here are a few of the 1999 RE-Wrenches replies. Someone wrote that a company named “KISS” (Keep It Simple Solar) has a patent for a solar powered computer, but I couldn’t confirm it. He also wrote that KISS sold out to Advance Power (Power Experts) around 1997 or 1998. In 199, Sunwize offered a PV module to power PCs. IBM had an interesting patent for an amorphous PV module that was behind the PC’s LCD screen. Office or outdoor light that passed through the computer screen's non-energized pixels and onto the PV module could charge an internal battery or capacitor. That was more than 15 years ago yet there are still no computers or hand-held screen devices that do not require plug-in charging.

Phil Karn reported: I dunno who was first, but right now (1999) I have three Linux systems running on solar power all day, crunching Seti@Home datasets. There should be a separate competitive category for solar-powered SETI. The last time I measured power consumption with a Brand Electronics power meter my three computers plus networking gear (various Enet hubs, cable modem, ADSL box, GPS receiver, etc.) was about 330 watts. That's with Seti@Home running on all four CPUs (one machine is dual-CPU). Idle CPUs draw significantly less power, at least under Linux. I figure my home computers use about twice as much energy as my EV1 (see Note) does on a normal daily commute (about 10 miles round trip). SDG&E comes to swap my meter tomorrow. Then I'm clear to enter SELL mode. I have an interesting saga to tell about doing net metering with TOU tariffing; perhaps I should write that up too. The bottom line is that little old me was able to get a big bad utility to change a tariff just for me. Of course, it helped to have California state law on my side. My note: The EV1 was General Motors’ wonderful electric vehicle that they recalled and destroyed. See

Walt Pyle reported: I doubt that we were the first, but we powered our Imsai 8080 that was built as a kit from a bag of parts in 1976 with 10 each 10-watt Solarex silicone-potted single-crystal silicon modules. Those PVs charged a pair of 8-volt locomotive batteries with 12 volts tapped off and one cell not used. I used a Tripplite square wave inverter to go from 12vdc to 120vac that rattled the transformer windings of the Imsai. Later, we replaced the Tripplite with a Trace inverter.

Dan reported: We manufactured the first solar power PC and won awards for it in 1995 at the University of Florida in Gainesville. See*/

Someone whose name I can’t recall reported: FWIW, I used a solar powered Apple IIc with LCD panel on archaeological projects in 1984.

Derek Dexheimer reported: I doubt this is what you want, but I remember playing with a solar panel and my old Tandy 200. This was probably 1988 or so. It was just me fiddling around for a couple days.

Dan Metcalf at reported: Check out my home web site. The whole system is 100% powered off of solar power.  I've been running this solar electric experiment since December 1998 and powering the web site since May 1999.  The system never runs on grid power unless I'm going to be away from home for more than 2 days, and so far that's only been a couple of times.

Loren Amelang reported: I built a Z-80 S-100 system in 1981 which took DC power from the PV array that powered my home and well near Philo, CA. At that time there were 6 each 35W Solec panels in a 12V array. A multipole switch moved several lead acid batteries between 12V charging configuration, and the complex series array needed to get the 8 and +-16 Volt S-100 supplies. It had the PerSci servo-actuated 8" DSDD dual floppy drive for the fastest response short of a real 14" hard drive (which I didn't feel I had enough PV to run). It had a 12", 12 VDC monochrome serial ASCII terminal, and/or a directly connected (5 inch?) monitor from an Osborne. The original Epson 9-pin printer (made entirely from metal!) ran from a Heathkit inverter when needed. It even had a 12VDC 300 baud modem, but there was no phone line. To access Micro-Net I would plug the ASCII terminal and the (acoustic coupled) modem into my pickup and drive to the only pay phone in the next town. When the Tandy Model 100 (the original laptop) came out, it made this payphone surfing much simpler, and became the serial terminal for the S-100 box. That same Tandy 100 is still plugged into my PV system right now, logging data from my water system! Today I have various modern laptops, plus a P200 ISA backplane system running from an Aquire, Inc. ACE-870C 24VDC input switching power supply with all the normal regulated PC voltage outputs. And the original flat panel Apple Studio Display, 25 watts for the most beautiful 15" screen image I've seen anywhere, plus it takes S-Video in from the satellite system. See a video about Loren’s off-grid home at

These replies plus email and snailmail exchanges with thousands of PV users confirmed what I had imagined. Back before the turn of the century, there were thousands of PV powered PCs ranging from the computers used by Home Power magazine founders and many of their readers, to Peace Corp volunteers and missionaries in developing countries, to techies and amateur radio operators, to people who just happen to have their PC plugged into their PV powered home.

Joel Davidson
June 16, 2014

Friday, June 13, 2014

How did the PV Bulk Buy start?

In the 1970s, I was living off-grid in the Boston Mountains of the Arkansas Ozarks. I did some PV module group purchases in 1979, but the first PV Bulk Buy was August 1980 when I bought 58 Arco Solar 33-watt modules from Steve Baer at Zomeworks. 4 modules were added to my PV system and rest were for a few other people in northwest Arkansas.

In 1981, I presented a paper about my PV powered home at the International Solar Energy Society (ISES) Conference in Philadelphia. At that conference, I met Paul Maycock, Karl Boer, Stephen Strong, and several other PV pioneers. I also met Rodale Press editor, Michael LaFavore. In the Summer of 1981, Michael visited my home and wrote an article about it in the November 1981 issue of Organic Gardening magazine. See

Michael’s article encouraged more than 900 people to write to me asking how they could start using PV. Hundreds more people wrote to me after reading about my PV system and the PV Bulk Buy in Solar Age magazine, Christian Science Monitor, Progressive Architecture, Mother Earth News, and other publications. By the end of 1981, I was organizing regular PV Bulk Buys and shipping more than 100 of the “new high-power" Arco Solar 35-watt modules at $375 per module including UPS charges. By today’s standards, this would be a small order of very expensive solar modules, but in 1981 less than $11/watt was the lowest price for do-it-yourselfers.

My supplier, Steve Baer, told me to buy directly from his distributor and introduced me to William Lamb. Bill Lamb was friends Bill Yerkes who founded Solar Technology International in 1975. Atlantic Richfield bought Yerkes PV company in 1978 and renamed it Arco Solar making Wm. Lamb Company the world’s first PV wholesale distributor.

By January 1982, my PV Bulk Buy mailing list had grown to almost 3,000 people and I had switched from mailing almost monthly letters to everyone to publishing The PV Network News on newsprint to announce regular Bulk Buys and share info with do-it-yourselfers.

The PV Network continued to grow as word spread about the PV Bulk Buys. March 1982, Bill Lamb invited me to California to tour Arco Solar’s factory located in Chatsworth at that time. Bill and the Arco Solar people were big supporters of the PV Bulk Buy and gave me an Apple II computer to facilitate publishing the PV Network News. I couldn’t resist opening the computer chassis and connecting my home’s 12-volt DC PV system directly to the computer’s DC circuitry. In those days, PV pioneers were opening radios, tvs, record turntables, tools and other 120-volt AC equipment to bypass input transformers and connect equipment directly to their PV systems.

By the Fall of 1982, I was regularly shipping more than 1,600 Arco Solar modules to do-it-yourselfers all over the United States but mostly in California. I wanted to offer another brand solar module so I contacted John K., who was working for Photowatt, a French company with a PV module assembly factory in Arizona. John liked the bulk-buy idea as did David K., a PV equipment distributor, so we did a Photowatt module Bulk Buy shipped from David’s shop in northern California. Later, I also offered Kyocera modules.

My Ozark home was off-grid with no phone and the only way to communicate with me was by mail. I didn't to deal with personal checks so people had to pay for their PV modules with cashier’s checks or postal money orders sent to my Pettigrew, Arkansas General Delivery address. This was old-style mail-order. (Remember the ads in magazines and back of comic books?) People were very trusting. I don’t think this could happen nowadays because rip-off artists have just about killed people’s trust.

I lived several miles from the paved roads or as locals would say “so far back in the woods that I used hoot-owls for roosters.” Once a week, I would drive my truck or ride my horse to the post office in Pettigrew to get my mail and the PV Bulk Buy orders. Back then, Pettigrew was just a 12x12 feet post office where the spit-and-whittle old-timers met, a general store, a few houses, a repair shop with a trailer home out back, and a junkyard full of rusting cars and trucks. Pettigrew is still just a little settlement on Route 16 near the mouth of the White River in the beautiful Arkansas Ozarks.

Once a week, I would drive to the bank in Huntsville, Arkansas to convert Bulk Buy checks and money orders into one big cashier’s check and then mail it along with people's shipping addresses to Bill Lamb in North Hollywood (not "Hollywood") California. Bill would ship the modules promptly and everyone was happy. Back then Huntsville, the Madison County seat, had about 1,200 inhabitants and the county was the 2nd poorest in the 2nd poorest state (they use to say "thank god for Mississippi"). Today, Huntsville has about 2,400 people and Arkansas is the 3rd poorest state. Madison County remains poor.

Interestingly, those early PV Bulk Buy modules are still producing solar electricity. See

In November 1982, after living in the Ozarks for 10 years, I decided to give up subsistence living and do what I could to make society better. Bill Lamb encouraged me to return to Los Angeles where had lived 1966 when I got out of the Army until 1970 when I moved to Oakland, California. LA in the 1960s was fantastic. I had a wonderful time. I liked the weather, the beaches and the people so I returned to LA LA Land and worked as Bill’s sales manager until he died in 1987. During that time, the PV industry grew rapidly thanks to Jimmy Carter’s pro-solar policies. Ronald Reagan’s anti-solar policies killed the federal tax credit for solar December 1985, but PV had taken root and nothing could stop its growth.

George Orwell's 1984 did not happen as predicted. In fact, 1984 was a great year for me. I was so busy selling PV that I asked Paul Wilkins, a New Mexico PV pioneer, to take over the PV Network News. Paul continued sharing PV information until he died in 2010. Also in 1984, Fran and I got married and we bought our home. That same year, the defunct National Energy Journal awarded me Solar Man of the Year and Greg Johanson and I built the solar vehicle that established the Guinness World Record category and started the international pastime of solar car racing. See

I was fortunate to have caught the PV wave of the future at the right time and have worked on a lot of interesting PV projects with some wonderful people. I no longer sell PV equipment, but I still like to work on interesting solar projects so email if you need a PV expert.

Joel Davidson

Monday, June 9, 2014

What happened to and SOLutions in Solar Electricity?

We’re still here - just different.

In the 1970s, I started SOLutions in Solar Electricity as a mail-order company when I was living in the Arkansas Ozark mountains. In the 1990s, I started when Y2K concerns and the California solar rebate had people searching for low-cost PV. See the Internet Archive Wayback Machine record at

For 35 years, I worked in the PV industry as "one of this country's most experienced, hands-on pioneers" according to the Rocky Mountain Institute. I still work on unique PV projects so email if you are doing something interesting and need an PV expert.

How did SOLutions in Solar Electricity and the PV Bulk Buy get started?...(more later)