First report: Cogen Feasibility study at PJ Dave
Bio Power Systems Limited (BSL) has been engaged by Energy, Environment and Development Network for Africa (AFREPREN/FWD) in partnership with P J Dave Flowers Ltd (PJD) to scale up energy efficiency at PJ Dave Flowers.
The kick off meeting of the Cogen Feasibility study project was hosted by PJ Dave Flowers Ltd. in the company’s board room on 14/3/2016. The main objective of the Project is to provide P J Dave Flowers Ltd with advice on the renewable energy options that can be developed on the farm leading to reduction on the dependence on the national electricity grid and fossil fuels for productive energy supply.
The team has visited the various sections of the 45 ha flower farm located at Isinya (Latitude 1.688093°, Longitude 36.859901° Elevation 1639m) about, 60km south of Nairobi in Kajiado County along the Athi River–Kajiado road.
ANALYSIS OF ENERGY DEMAND AND SUPPLY
The main sources of energy at the farm are electricity and fossil fuel.
Electricity –This is the main source of energy which is supplied by the national grid. This is supplied to the farm through five metered supply points.
Fossil Fuel –Energy derived from both diesel and kerosene has a significant contribution in the production at the farm.
Diesel for Power generation–This is used to run stand by generators during times of grid power outages. A total of 1450kva diesel generators have been installed at three locations on the farm:
Kerosene- This is used to power the boiler for heating water mainly for the propagation green houses. The kerosene boiler is operated every day to maintain the temperatures in the propagation greenhouses above 28oC.
Biogas – Used in a biogas generator that is connected to two borehole pumps. However, the digester is currently under rehabilitation and one borehole has been shut down because of low water yield arising from the prevailing draught.
ENERGY CONSUMPTION & COSTING
The consultant has reviewed the historical data on energy consumption for the farm from two past energy audits reports covering the period Jan 2010 to October 2014 and the period from Nov 2014 to Dec 2016 is analysed by the consultant.
The table below shows the energy consumption and costs trends.
DEMAND AND COST TRENDS
PERIOD kWh/yr Ksh/yr
Jan 2010-May 2011 4,167,230 63,699,213
Jan 2013-Oct 2014 4,784,629 90,618,635
Oct 2014-Dec 2016 3,704,960 61,328,494
POWER DATA ANALYSIS & FINDINGS
In order to monitor the overall energy consumed by the farm over a 24 hour period, a Power Energy Logger (PEL) was set up at the main incomer to record power parameters. From the logging power and energy data have been analyzed as follows:
Logging point Measured Power Measured Energy
Min (kW) Max (kW) kWh
Main intake 194.4 527.2 8,643
Riverside borehole 28.97
Mombasa Camp 0 42.81 283.8
At the main power intake, the farm consumes a total of 8,643 kWh (8.643Mwh) of energy per day. Assuming daily power usage profile is similar on day to day basis, the energy consumption for one month is 259,290 Kwh/M. Annually, the consumption is 3,111,480 kWh/yr. This closely matches the energy consumption charged in the recent power bills of 2016. During the year, 2016, the charged units were 3,767,490 kWh/yr.
Energy use Profile
The energy use profile over a 24 hour period is presented in the chart below. Over this period, 4,283kWh are used between 7.00am and 5.00pm. This is 50% of the total daily consumption.
The reason for high demand at night is that the main loads are operated for 24hours, seven days a week.
FUTURE ENERGY DEMANDS
Energy use grows with the growth of the farm. At 45Ha, the farm has almost reached its growth limit.
The average energy demand in 2015 and 2016 has been 3,704,960kWh/yr which is about 23% drop from the demand in the previous 4,784,629kWh/yr. See graphs below.
The energy usage is expected to remain nearly the same as the farm size has remained constant over the last eight years. Load growth is not expected to be significant.
As the grid stability is expected to improve, demand on diesel generation is expected to maintain a decline
This paper is available on an exchange basis. If you find
it to be useful,
we encourage you to send us any relevant publications from your
organization. To request for the full paper, please fill in the
publications request form
View the listing of Other Working Papers