Sustainable Living
Photovoltaics
Embedded Files
It would not be possible to inhabit Mikro Horio comfortably in the winter without first installing electricity, which is essential to a heating system. We needed to identify a power source and to wire the buildings.
By 2001, the public utility power lines passed by the eastern boundary of our property, on their way to service neighbors to the north. Obtaining our power from this source, however, was rejected out-of-hand; we did not want to see power poles and lines marching across the land, and, more importantly, we had strong feelings for developing an independent, ecologically-sound system. (The electricity lines were not extended down the road on Divlaka Bay, to our south, until several years later.)
Initial investigations on the subject, before our 2001 return to Greece, focused on wind power as a relatively inexpensive proposition suitable for a location, such as ours, that was legendary for the strength and duration of its winds. Christos still remembers an enticing article in Mother Earth News with the headline, "600 watts for 600 bucks."
Further investigations after our return to Greece included photovoltaic (PV) panels. Kythnos, it turns out, is in the vanguard in the development of alternative power sources. Greece's Public Power Corporation has established an experimental park with both PV panels and large-scale wind turbines on the island; we visited both and talked to the local engineers.
We also consulted scientists in the Greek Center of Renewable Energy Sources, who run a European Union-funded project of PV-generated power for a settlement of a dozen summer homes on a cove near ours. These scientists and engineers steered us away from wind power, pointing out that, although wind is plentiful, it is of the wrong kind. It is not a steady wind; it comes in great gusts and from ever-shifting directions. Under such conditions, a wind turbine would require continuous maintenance and repair, with the potential of lengthy "down" times.
PV panels, by comparison, have no moving parts, carry a warranty of 20 years and a potential life even longer. In the long run, they would be the cheapest and most reliable system.
Wiring of Buildings
We anticipated it would take at least two years to wire the buildings, build a utility space to house batteries and assorted equipment, and prepare a base on which to mount PV panels. With this in mind, we took two actions: first, we purchased a gasoline-fueled generator so that in the interim we would have power for a concrete mixer and hand-held power tools; second, we engaged the services of a mechanical/electrical engineer to advise us on photovoltaics plus wiring, heating and plumbing. George Cavoulacos of TEKEM became a friend who provided us with excellent professional advice. With his guidance, we proceeded to design the utility spaces, housed in GBB IV, which was constructed in 2004.
The following spring, we wired the buildings. This was a project fraught with potential disaster on the aesthetic level. The type of construction employed in our buildings precluded the post-facto introduction of wires and conduits under the plaster. Therefore, all wiring had to be surface-mounted in channels commercially available for this purpose. The prevalence of non-90-degree angles in all spaces meant that extra care was needed in joining the channels.
At this point, deus ex machina appeared in the form of Dr. Frank Forstmann. A mutual friend had invited Frank to our land a couple of years earlier — he came the day after he retired as professor of physics from the University of Berlin. At that time, Frank, seeing that we did most of the work ourselves, offered to help from time to time. The offer was renewed just as we were trying to figure out the wiring, and it turned out that Frank knew electricity—not just from the theoretical perspective, but from having rewired his apartment in Berlin by himself.
Georgi Popov, our Bulgarian jack-of-all-trades assistant, was also pressed into service. Including Christos, it took 35 days to do the work. The team started in each room by planning the path of the channels and the location of switches and plugs. Georgi installed the bottom half of the channels and the business end of plugs and switches. Frank followed behind with the wires, and Christos came last, covering the channels, plugs and switches. We dubbed these three stages the "hard" work, the "smart" work and the "art" work. With a German accent, it rhymes.
Each building has a fuse box, connected to the master box in GBB IV, with cables in conduits, buried underground in channels we formed using PVC open gutters (half cylinders). One set of gutters was placed face up, the conduit laid in, and then it was filled with sand and covered with a second, face-down set of gutters. We hope that the sand will provide protection from rodents.
Installing the PhotoVoltaics
By late September, 2005 all was ready, including the storerooms and a concrete platform to receive the PV panels; on November 12 of that year, a crew of three headed by Marios Sigalas of PHOTOVOLTAIC came and installed the entire system in two days. The system comprises the following:
Twelve panels of 150 watts each facing directly south, set at an angle close to the perpendicular at noon of the sun on winter solstice.
The panels are grouped in two sets of six and power flows into two solar charge controllers, wall-mounted units that regulate the flow into the batteries, cutting it off when dangerously high. They are equipped with a display that provides information on the flow into and the status of the batteries.
Twelve 2Volt batteries connected in series (for a total of 24V), which are located in a small, well-vented, dedicated storeroom. This is the only component of the system that requires maintenance. They need to be checked periodically and the water topped up as needed.
From the batteries, power flows through a 3000 watt inverter to the main fuse box. The inverter converts the 24V direct current of the batteries to 220V alternating current.
The generator back-up system follows a similar path. Power from the 6000 watt generator (also located in a dedicated room) flows into the batteries through a separate control unit. The panels and the generator can charge the batteries simultaneously. We can operate equipment, such as an arc welder which requires power greater than the 3000 watts provided by the inverter, by plugging it directly into the generator.
The PV system supplied us with adequate power for our needs for a decade. But as our needs grew, we decided to install additional panels in 2017, and also obtained new and more efficient batteries.
Power Usage
In planning the PV system, we eliminated from the outset appliances incorporating high wattage resistance elements:
We continue to use bottled gas for cooking, as we have done in past years. We use a two-burner stove top; an outdoor wood-burning oven completes our cooking needs.
We installed a solar water heater. The burner for the heating system provides back-up energy on cloudy days.
We planned for and purchased an A-rated clothes washer which receives hot water directly from the solar water heater. (Most washing machines in Greece heat the water internally; only recently have models such as ours become available in this country).
Other than the above, we planned for and now operate what seems, after years of kerosene lamps and flashlights, a luxurious household including: about 45 light fixtures using economy light bulbs, four ceiling fans, a microwave oven, hair dryer, A-rated full-size refrigerator capable of supporting our summer beer demands, three pumps that are crucial for the plumbing system (a pressure pump and two float-activated pumps that move water from holding tanks to storage tanks, various tools (concrete mixer, concrete vibrator, cutting disk, drill, jig saw), radio, television, DVD player, computer, and assorted battery chargers.
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