PDA

View Full Version : Energy (Cost) Savings: Your pocket, your nation, your environment



ajbabe
13th January 2012, 04:45 PM
In our first feature for the year 2012, we shall learn more about the Electricity billing system in Ghana and the steps we could take to reduce our energy consumption and consequently our monthly electricity bills.

Energy is considered the prime mover for the technological development of any nation and electrical power is the foremost source of energy. However, electric power as a source of energy requires tremendous capital and human investment to realise its benefits. Capital is required for the construction of generating stations, transmission and distribution lines as well as power and distribution stations.

Investments in capital and human resources are required to operate and maintain the power system to achieve optimum performance. For most developing countries such as Ghana, capital is not readily available and therefore, we have to rely on external capital with its inevitably harsh terms and conditions. Consequently, the supply authority has to generate sufficient revenue to pay back loans and maintain the system.

These objectives could only be achieved with the introduction of an appropriate tariff for the various classes of consumers by Regulatory Authorities who ensure that the customer gets what he pays for.

In Ghana, electricity tariffs are Public Utility Regulatory Authority (PURC)-regulated and customers are categorised into the following groups for billing;

Residential
Non Residential
Industrial Customers
The first two are known as Non Special Load Tariff (SLT) customers and the last are SLT customers. The Utility in Ghana adopts a single-tier tariff structure for billing residential and non-residential consumers and a two-tier tariff structure for industrial consumers.

The supply authority bills consumers for energy by the installation of revenue meters. Until recently in Ghana, these revenue meters were mainly electromechanical meters but these are being replaced with electronic pre-paid and post-paid meters. These meters are either single or three-phase, depending on the demand load of the consumer.

Residential and Non Residential Customers
The tariff structure for billing consumers is such that after a particular threshold (normally published by the Utility or indicated on your electricity bills), the charge per unit of energy consumed is graduated.

The customer can save on bills by monitoring consumption patterns to remain (as far as possible) within the lower consumption bands. In addition, consumers can make significant energy savings by adopting simple practices such as using energy efficient lights and electronic appliances as well as switching off lights and appliances when not required.

For some households, equipment such as irons and water heaters require a lead or 'warm up' time to reach their operational temperatures/status. So, for pressing irons for example, it is best to iron a number of items at one time and not individually.

In some developed countries, the supply authorities apply varying tariffs during different times of the day and night with higher tariffs charged during the peak load periods. This period generally falls between 7pm and 10pm when most working people are home.

This influences consumer consumption patterns and encourages consumers to level out their demand and shift some tasks that require a reasonable amount of electricity (e.g. washing machines) to operate after peak hours. Though this practice is not yet applicable in Ghana, chances are that with improvement in metering technology and shortfall in generation capacity, the supply authority will ultimately find the need to introduce such a policy to bridge the widening gap between generation capacity and demand.

Industrial Customers
Industrial load forms the major component of the Electricity Company Ghana's (ECG) total energy consumption in the southern part of the country, especially in the cities. Efforts to develop energy-efficient technologies have been focused on the most energy-intensive industries. These include food and agriculture, textiles, mining and metals and the oil and petroleum industries.

Industrial and commercial consumers that have SLT meters installed for revenue billing have several options open to reduce their energy consumption. The tariff structure for SLT metered consumers is as follows:

Charge for energy consumed (kWh)
Charge for maximum demand for billing period (kVA)

Surcharge for the low power factor operation
Maximum demand does not depend solely on power consumed but on other factors that could be controlled by the consumer. Maximum Demand is calculated and billed by a kilowatt (Kw) demand meter, which records the highest kW value consumed in a given time period, over a monthly billing cycle. The purpose of controlling the demand is not to exceed the contracted maximum demand limit.

The maximum demand for a given period could be reduced by instituting a loading programme so that short-time heavy power consuming equipment (or equipment with high start-up currents) is not switched on simultaneously, but rather in stages. Another way to save on maximum demand is to shed non-critical loads by using Smart systems and distributing these loads over time. This practice would ensure that the maximum demand recorded for any given billing period would be as close as possible to the average demand.

The power factor surcharge is imposed on a certain class of consumers by the Utility, to urge them to take appropriate steps to reduce inductive or wasteful loads. These loads are characterized by inductive machinery such as motors and air-conditioning equipment which draw so-called lagging power factor currents. In Ghana, the Utility imposes surcharges on consumers who have a load power factor below 0.90.

Consequently consumers have a choice to either continue paying this surcharge or take steps to install equipment and devices that would correct the power factor to the desired limit. This can be done using devices such as capacitor banks. This correction also benefits the Utility since they would have enough energy capacity from the saved consumption to feed other consumers.

SLT consumers are also advised to use energy-efficient motors and motors with variable speed drives to enhance the performance and thus reduce energy consumption.

Conclusion
This feature has outlined the importance of energy billing in any power system and explored the benefits to be derived by both customers and the supply authority.

The consumer should install energy efficient equipment and take deliberate steps to ensure the efficient utilization of energy whilst the utility puts measures in place to reduce revenue losses.