Objective
To demmonstrate the performance and reliability of a 25 kWp stand-alone pv plant supplying electricity to two small villages on the Greek island of Arki. The pv array may be extended in the future, and a wind generator may be added to provide additional power.
Average annual production is about 13000 kWh.
The main problems encountered were:
- with the batteries (precipitation)
- with the modules (short circuits, leading to their destruction)
- with the charge regulator (burned out-replaced)
- incomplete battery charging leading to reduced plant autonomy.
The above problems (primarily the last one) led to the decision to install a Diesel generator set to boost charge the batteries and thus maintain continuity of supply.
The problem overall is under investigation and steps will be taken to improve the situation.
The addition of a number of panels so as to increase the power output of the solar field is being seriously considered.
As the only electricity generation and transmission company in Greece, PPC is promoting an electrification programme for a number of small remote Greek islands which have no electricity supply.
This is expected to increase the standard of living of the island inhabitants and revitalize local communities.
In this project a 25 kWp array provides electricity for two small villages on Arki island, about 30 km south of the island of Samos. The total population of Arki island is about 60 people in winter and 100 in summer, and the daily energy requirement is 50 kWh in winter and 100 kWh in summer. Due to the relatively high cost of pv generated electricity, consumers are encouraged to use high efficiency domestic appliances, and were generally educated about the use of electricity.
The pv plant consists of 25 kWp of PHOTON TECHNOLOGY (Belgium) polycrystalline modules, a self communated (dc/ac 30 kVA) inverter (220/380V/50HZ ac) designed by AEG, and a 1440 Ah/210V storage battery. Assuming 11 hours of sunshine per day in the winter, the array should have a daily output of 60 kWh in winter and 112 kWh in summer.
The array consists of 714 modules, each with a peak power of 35 W. In view of the possible future expansion of the array, the infrastructure and civil works were designed for a 40 kWp generator.
The dc input to the inverter either comes from the storage battery or directly from the pv array. If a wind generator is installed in the future, the inverter will have to operate as an ac-dc rectifier, so that excess wind power can be used for battery charging. This has been taken into account when designing the inverter.
The project has been monitored for two years in accordance with the monitoring guidelines issued by JRC Ispra. Monitoring data are available at ispra for the periods from October 1988 to September 1989 and from March 1990 to December 1990.
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
10436 Athens
Greece