Energy and payback

How many years before an investment has paid for itself? Enter what it costs and what you save each year — in kroner or in kWh with your own price.

The explanation is shown. Quick: investment and saving. Advanced: price increase and lifetime, what it means if the numbers slip — and year by year.

Your numbers

Investment

What it costs to buy and have done.

I know the saving as

Saving per year

More options: Price increase, Service life

Price increase per year

Your own estimate. 0 = same price every year.

Service life

How long it lasts. 0 = not included.

Payback period

10year

About 10 years and 0 months.

Saving in the first year

6,000.00DKK

160,000 / 6,000.00 = 10 yearSimple payback period: how many years of savings the investment equals.

payback time = investment / saving per year

Simple payback period — without interest and without price increases.

saving = kWh saved · price per kWh

n = ln(1 + I · g / B) / ln(1 + g)

With an annual price increase g: I is the investment, B the saving in the first year.

Interest on the money and maintenance are not included. Include them if the decision is a big one.

Calculators from the education programmes that work out the same topic in more detail.

Payback on a workshop investment
How many shoeings — and how long — before an investment has paid for itself?
Profitability — payback period for energy optimisation
How long does it take for an investment in energy optimisation to pay for itself through fuel savings?
Tax depreciation of operating assets on the reducing balance
What is the most the business can depreciate on its operating assets this year, and what is the balance afterwards?
Straight-line depreciation of fixed assets (accounting)
What is the annual depreciation, and what is the asset's book value after a given number of years?

In depth: more numbers and “what if”

What if the investment or the saving is 20 % off?

Saving per year	Investment 48,000.00	Investment 60,000.00	Investment 72,000.00
4,800.00 DKK	10 year	12.5 year	15 year
6,000.00 DKK	8 year	10 year	12 year
7,200.00 DKK	6.7 year	8.3 year	10 year

Year by year

Year	Saving that year	Saved in total	Still to go
1	6,000.00	6,000.00	54,000.00
2	6,000.00	12,000.00	48,000.00
3	6,000.00	18,000.00	42,000.00
4	6,000.00	24,000.00	36,000.00
5	6,000.00	30,000.00	30,000.00
6	6,000.00	36,000.00	24,000.00
7	6,000.00	42,000.00	18,000.00
8	6,000.00	48,000.00	12,000.00
9	6,000.00	54,000.00	6,000.00
10	6,000.00	60,000.00	✓ paid back
11	6,000.00	66,000.00	✓ paid back
12	6,000.00	72,000.00	✓ paid back