Your Mumbai Office's electricity bill is going to fly through the sky from June'08.

With the increase of MERC tariff since 01.06.2008 the big commercial offices are going to be hit heavily. The result of hike is more than 80%.

Two part tariff:

The electricity tariff is devided into broadly two part: fixed cost and variable cost. The taxes ,duties, FAC and TOD are seperate.

Fixed Cost:

The fixed cost is calculated based on the Billing Demand recorded in a month by the energy meter. It indicates what was the maximum demand during the month. This can be explained little separately.

Say you have an office with 30 tons AC fitted at several halls and cabins.

The average specific energy consumption is 1.3 KWH / tons to 1.8 KWH / tons.

Bigger machines are more efficient than smaller ones and needless to mention that the more the dirty Acs the more electricity it consumes.

So for 30 tons AC when runs at full blast on monday morning it takes

30*1.6 = 48 KWH and suppose the power factor you are maintaining for your premises is just 0.9 then 40 KWH = 40 / 0.9 =53 KVA.

The lighting and computer ,printers, fax machines takes another 10 KVA load . So the billing demad is going to be 53 +10 = 63 KVA. You are to pay 65% of total fixed cost @ RS:374 / KVA

Your Bill for the month (Before June'08)

Considering a 9 hours office usage for 30 days in month, your bill was like this.

Fixed Cost = 374 (rate) *63 (billing demand) *0.65 (65 %) =Rs:15315.00

Variable Cost = 4.99 (rate) * 63 * 0.9 (power factor) * 30(days) * 9(hours)

= Rs: 76391.00

Taxes etc: The Fuel Adjustment charges , Taxes and duty and Peak energy charges will be around Rs:15000.00 (does not varry much)

Power factor penalty = 0 as you are just maintaing 0.9.

So total you will pay = Rs:106706 .00

Lets see the same Bill for the June'08 onwards

Fixed Cost = 150 (rate) *63 (billing demand) * 1 (100 percent) =Rs:9450.00

Variable Cost = 10.78 (rate) * 63 * 0.9 (power factor) * 30(days) * 9(hours)

= Rs: 165031.00

Taxes etc: The Fuel Adjustment charges , Taxes and duty and Peak energy charges will be around Rs:25000.00 (variable cost increases 115 %)

Power factor penalty = 0 as you are just maintaing power factor 0.9

So total you will pay = Rs:199481 .00

The bill is hiked by almost 87%

Tighten your belt:

Tighten the AC first.....

AC costs 80% of your bills. So the best thing can be done is check up their health and act accordingly. Dirty AC costs more power consumption. In dusty mumbai atmosphere it is an apt decision to replace the external air cooled condenser tube nests in every five years. The payback is hardly a couple of months. Other allied jobs like routine cleaning of indoor filter units , luricating the bearings etc pays substantially to your bottom line.

Power Factor incentive

If power factor can be maintained beyond 95% a handsome incentive can be achieved as high as 7% of total bill (excluding taxes and duties). The amount for the above bill is Rs:12230.00 . When power factor is improved from 0.90 to 1.00 the billing demand will also be reduced by 10% (6.3 KVA) . This will also add to your saving (@ Rs:150.00 ).

Therefore, the total saving will be Rs:12230 + Rs:950 = Rs:13175 . For the whole year (12 months) this is equal to Rs:158100.00 which is roughly 80% of a month's bill.

Now for the above case for improving power factor from 0.9 to 1.0 an additional power capacitor of 27 KVAr will be required. The setup cost etc @ Rs: 500 / KVAr will be Rs:13500. The payback is just a month !!!

Just imagine how much opportunity will be lost if this is not claimed. And once done you can say that once in 15 months you get one bill paid free by it.

Tighten your light etc:

There is not much left here for you to achieve. Mostly the incandescent bulbs are rightly replaced by CFLs now-a-days. If not done in your case go for it immediately. The T12 tube lights may be replaced by more efficient T5 tube lights.

For more querries call me at berasomnath@gmail.com

Bye

S. Bera