Renewable Energy Based Rural Electrification
Funding from the Ministry of Foreign Affairs (MOFA) enables PICHTR to continue its efforts to advance sustainable development in the Pacific Islands. The focus of this program is centered around identifying appropriate renewable energy technologies and integrating these technologies into the energy system planning process of an island nation.
PICHTR is working on the development of alternate energy systems, in combination with each other and with storage systems, to broaden their applicability within utility and stand-alone environments. Current MOFA funding will enable PICHTR to complete the final design, acquisition and installation of a village power system in Fiji. A test facility at Kahua on the Big Island of Hawaii has been completed, and personnel from the Fiji Department of Energy will receive the necessary training to operate the village power system at the Kahua facility. Upon completion of the construction and shakedown, the Fiji Village Power facility will be turned over to the Government of Fiji. Successful implementation of the Fiji facility may lead to other Pacific island nations utilizing this technology in their countries.
PICHTR has designed and constructed a Village Power Demonstration Training Facility consisting of PV modules, battery storage, wind turbines generators, power converter (inverter/controller) and diesel generator. The integrated system, which is supported by funding from the Ministry of Foreign Affairs (MOFA) of Japan, was designed for Pacific island applications and is used to evaluate components as well as to train potential users of similar systems.
The demonstration and training facility is located at the Kahua Ranch on the Big Island of Hawaii. The ranch provides housing for the workers, and their electrical power consumption patterns are similar to those found in remote villages throughout the Pacific. Given the long-term wind and solar data records available at the site, the system was designed to produce approximately 80% of the ranch's electrical load requirement with renewables and the balance with a diesel generator. Working with the Fiji's Department of Energy (FDOE), data was obtained to develop the conceptual design for a system for the village of Nabouwalu (Vanua Levu). Installation of the system began in July 1997 and has been operational since January 1998.
Potential applications of the Village Power system exist in other Pacific island nations as well as in Asia and South American countries.
Renewable-Energy-Based Rural Electrification for Pacific Island Nations
The Pacific Renewable Energy Rural Electrification (RERE) program is envisioned to be a joint Japanese and United States project to support renewable energy-based electrification for Pacific Island nations. Presently, there are three levels of service ranging from PV-lights to full AC electrical service.
Solar Home Systems for Remote Villages (Evening PV-Lights and Small DC Appliances)
Candles, kerosene lamps and dry cell batteries are used, in remote villages, for lighting and radios. Monthly expenditures (~ $5 to $20) yield an equivalent cost-of-electricity of ~ 2 $/kWh (US$ used here). Stand-alone PV-based solar home systems (SHSs) can provide cost effective lights and power DC appliances. In recent years thousands SHSs have been installed in every continent. While most of these systems work well, many are undersized and there is considerable variation in equipment cost and durability. The most important lesson learned has been that without an organization responsible for servicing equipment and collecting user fees projects will fail (i.e., units non-operational after a few months).
PICHTR has determined that the minimal system size, for a nominal load of 40 W of fluorescent lights and a power point for a small radio or appliance is: 75 Wp to 100 Wp of PV; 100 Ah, 12 V deep cycle battery with 8 A charge controller. Recently a design was developed for installation in a remote village in Fiji. Vunivau, the village selected by Fiji Department of Energy (FDOE), is typical of many rural farming communities in developing countries. In Vunivau each family of rice farmers lives in a home on or near their farm. This means that the homes are widely separated and difficult to cost-effectively supply with grid-distributed electricity, especially since these homeowners cannot afford large purchases of electricity.
Tests led to the selection of the Powerhouse units available from Solar Shell. These include Conlog prepayment meters. The meters require the insertion of a magnetic striped card for a timed period of use. To facilitate battery replacement and because of the high cost of shipping them long distances, flooded lead-acid batteries manufactured by Pacific Batteries (in Suva) were selected for the Vunivau project. Methodologies for field installation, sizing PV arrays and determining their orientation were also developed by PICHTR. For Vunivau it was necessary to select 100 Wp of PV to guarantee service during the low insolation winter months. FDOE installed sixty units in January 2001. A technician trained by PICHTR maintains equipment and pre-payment cards (user's fees) are purchased at the nearest post office. Fees collected by FDOE will cover maintenance and replacement costs for the equipment donated by the Ministry of Foreign Affairs (MOFA) of the Government of Japan.
Small
Distributed PV-Hybrid Systems for Villages with Cottage Industry (~ 1 kWh/day/household)
PV-based hybrid systems are envisioned to electrify clusters of households in off-grid villages with cottage industry. Simply stated, the idea is to connect hybrid systems like the ones used by off-grid single residencies in Hawaii to several village households through a small grid. In Hawaii, hybrid systems consisting of PV arrays, inverter, battery and fossil fuel generator sized at 2 to 5 kW have been used since the 1980's in off-grid residencies. These systems produce enough AC electricity to support as many as 10 remote village households including cottage industries. The "small distributed PV-hybrid power systems" or hybrid-home-systems (HHSs) can supply continuous AC electricity to villages that need and can afford the service. This concept represents an evolutionary step from solar-home-systems (SHSs) like the units installed in Vunivau. To insure sustainability, either system must be serviced by organizations responsible for operation and maintenance and the users must be able to afford the service.
There are three main prerequisites for the deployment of HHSs:
- The maximum distance from the inverter source of AC power to the residential user is about 150 meters when the distribution voltage is 240V. This means that village housing density must be sufficiently high that distribution costs are not excessive.
- The system will require intermittent service by a person trained to fuel and maintain the diesel gensets, water the battery and place inverters in and out of service.
- An organization must be available for the collection of funds from the sale of electricity.
PICHTR is in the process of identifying an appropriate location in the South Pacific to design and install HHSs. A village of approximately 50 households with cottage industry requiring AC electricity service instead of the entry-level service provided with PV-lights would be an ideal site. It is expected that a service arrangement like the one described above for the SHSs in Vunivau, Fiji will be appropriate. The users will have to cover at least the costs of operation, maintenance, repair and replacement of equipment.
Hybrid Power System for Provincial Centers (~ 500 to 1500 kWh/day)
FDOE, with Public Work Department (PWD) and PICHTR, installed a 720 kWh/day renewable-energy-hybrid-power system at the Nabouwalu Government Station (offices, shops, ice-plant, bakeries, 30-bed hospital, school, post office, police station and village).
The system was designed by PICHTR. MOFA donated the renewable energy equipment. The site has an annual average wind speed of 6.2 m/s, and solar radiation with an annual average of 4.6 sun peak hours. The renewable energy hybrid power system consists of wind turbines, PV modules, 240 VDC flooded lead acid battery, and 100 kVA rotary inverter. Upwards of 70% is supplied with the renewable energy equipment and the balance with diesel generators.
As of January 1998, FDOE assumed ownership and PWD began operating the system with technicians trained by PICHTR. The system produces electricity at costs that are competitive with the true cost of electricity production with fossil fuels.
