Energy conservation opportunities at the defence forces memorial hospital.

Abstract

A study on energy conservation measures was conducted at the Defence Forces Memorial Hospital (DFMH) to identify opportunities which would cut down on the overall energy cost. This was guided by evaluation of energy cost distribution among the utilities in use. The biggest cost at 68 % of the total energy cost was out of electricity, 16 % diesel and 16 % LPG in 2017; 66 % electricity, 17 % diesel and 17 % LPG in 2018; 72 % electricity, 21 % LPG and 7 % diesel in 2019. The study narrowed down on the energy sources, lighting, water heating systems and incinerator, refrigeration and air conditioning, electrical motors and generator and laundry equipment. The main objective of the project was to perform a level II energy audit of the hospital which entailed reviewing energy bills, determining energy losses in the lighting system, assessing energy losses in water heating system and incinerator, evaluating refrigeration and air conditioning overall efficiency, evaluating electrical motors and generator performance efficiency, determining the power losses of the laundry equipment, identifying energy saving opportunities in the areas of focus and performing a cost-benefit analysis for identified energy saving opportunities. The method of executing the research project involved audit planning, general data acquisition, equipment testing and measurements, analysis of raw data and recommendations on energy conservation opportunities. The economic tools for determining the financial savings included the following: Capital Investment, Annual Financial Saving, PBP and ROI where possible while for the energy conservation opportunities, energy consumption technique was applied. The analysis identified that; in lighting, replacing all the 918 Fluorescent tubes with LED lights would result to payback periods of averagely less than 1 year, in the water heating system, the boiler was found to be underutilized with an output of 366.34 kJ/s and its current usage was 51.04 kJ/s. Instant showers were found to be consuming 187,447.5 kWh per year. The waste heat energy in the incinerator was found to be 490.42 kJ/s. For the HVAC system, one of the equipment was oversized at 4.6 kW, hence replacing it with the correct size would save the hospital Kshs 290,152.80 per year with a payback period of 1 year 11 months. It was also found that laundry and boiler feed water pumps motors had operating efficiencies below 75 % and would require regular maintenance and servicing. It was also notable that the same machines had low power factors which required appropriate measures to improve, example by insertion of capacitors for power improvement. The generator performance efficiency was 34.4 %. Power failure of the utility company (KPLC) costed the DFMH a loss of Kshs 130,489.60 (17 %) per year. In the laundry, the washer extractors and dryers consumed 608 kWh and 816 kWh per day respectively. If replaced with more efficient machines, financial savings of Kshs 1,527,120 and Kshs 3,406,495.70 per year for washer extractors and dryers respectively would be realized, with payback periods of 3 years 3 months and 2 years 6 months respectively. For the power quality, the maximum Total Harmonic Distortion (THD) was found to be 2.17 % which is within the recommendation of < 5 % according to IEEE Std 519- 1998.