ElecSimHub

Life-cycle cost comparator

Put 2–4 schemes on the same timeline: purchase price, no-load loss P0, load loss Pk, maintenance and discounting add up into one TOC figure — and you see the year the expensive scheme catches up. Everything is computed from the values you enter; no price, efficiency or loss coefficient is built in. Missing data shows “—” and is never replaced by 0.

Shared conditions (used by every scheme)Recomputed as you type — no button, no request

Same load, same tariff and same economic convention for all schemes — otherwise the comparison is not on one timeline. All fields are yours to enter; leave nothing empty.

Every field must be filled — no defaults are applied and incomplete schemes stay “unavailable”. → Operating hours (h/year)、Average load factor (%)、Energy price (CNY/kWh)、Discount rate (%/year)、Assessment life (years)

Scheme A
Scheme B
At least two complete schemes are needed for a comparison.
Scheme A
—
Unavailable — missing/invalid: Purchase price (CNY)、No-load loss P0 (kW)、Load loss Pk (kW)、Maintenance (CNY/year)、Salvage rate (% of purchase price)、Operating hours (h/year)、Average load factor (%)、Energy price (CNY/kWh)、Discount rate (%/year)、Assessment life (years)
Scheme B
—
Unavailable — missing/invalid: Purchase price (CNY)、No-load loss P0 (kW)、Load loss Pk (kW)、Maintenance (CNY/year)、Salvage rate (% of purchase price)、Operating hours (h/year)、Average load factor (%)、Energy price (CNY/kWh)、Discount rate (%/year)、Assessment life (years)
Life-cycle cost (TOC) comparisonpvF unavailable (fill the shared conditions)
SchemePurchase price (t=0)Annual loss costAnnual maintenanceLoss PVO&M PVSalvage PV (−)TOC (present value)
Scheme A———————
Scheme B———————
user input: Purchase price (t=0) · Annual loss cost · Annual maintenancederived: Loss PV · O&M PV · Salvage PV (−) · TOC (present value)

Present value, in the currency you entered. Columns marked “user input” come straight from you; the discounted columns are derived with the formulas listed below.

Break-even years — when does the expensive scheme catch up?
Break-even unavailable (need two complete schemes with a lower annual opex on the dearer one).

Break-even is the discounted-payback year of the extra purchase price: pvF(t*) = Δpurchase price / Δannual opex, i.e. t* = −ln(1 − r·pvF)/ln(1+r) for r > 0, and t* = Δpurchase price / Δannual opex when r = 0. “> N years” means it does not happen inside the assessment life — it is never shown as a smaller number.

Baseline = the scheme with the lowest purchase price. For every other scheme we solve purchase price + annual opex × pvF(t) on both sides and report the year the curves cross.

Computed charts
Computed charts(drawn from the results above, 0 requests)Scheme A: Purchase price (CNY)、No-load loss P0 (kW)、Load loss Pk (kW)、Maintenance (CNY/year)、Salvage rate (% of purchase price)、Operating hours (h/year)、Average load factor (%)、Energy price (CNY/kWh)、Discount rate (%/year)、Assessment life (years) · Scheme B: Purchase price (CNY)、No-load loss P0 (kW)、Load loss Pk (kW)、Maintenance (CNY/year)、Salvage rate (% of purchase price)、Operating hours (h/year)、Average load factor (%)、Energy price (CNY/kWh)、Discount rate (%/year)、Assessment life (years)
Chart unavailable — no complete scheme yet
Formulas and basis (everything is derived from your inputs)

Your inputs: purchase price, P0, Pk, operating hours h, load factor LF, energy price, discount rate r, life N, maintenance per year, salvage rate.

  • Annual loss energy = (P0 + Pk × LF²) × h [kWh/year] — iron loss is constant, copper loss follows the square of the load factor
  • Annual loss cost = annual loss energy × energy price [CNY/year]
  • Annuity present-worth factor pvF = (1 − (1+r)^−N)/r (pvF = N when r = 0)
  • Loss PV = annual loss cost × pvF ; O&M PV = annual maintenance × pvF
  • Purchase price is at t = 0 (not discounted); salvage PV = purchase price × salvage rate × (1+r)^−N
  • TOC (present value) = purchase price + loss PV + O&M PV − salvage PV
  • Break-even year t* solves: purchase price_A + annual opex_A × pvF(t) = purchase price_B + annual opex_B × pvF(t)
  • Fig 1 plots purchase price + annual opex × pvF(t) from t = 0 to N; the salvage credit is shown separately (Fig 2) and is not added to the curve.

Not modelled (stated, not hidden): tariff escalation, inflation, financing/tax/depreciation, replacement cycles, and monthly cash-flow granularity. The tool never substitutes a default price or coefficient for a value you did not enter.

Convention: purchase price sits at t = 0 and is not discounted; recurring loss and O&M costs are discounted with the annuity present-worth factor pvF = (1 − (1+r)^−N)/r (pvF = N when r = 0); salvage is discounted from year N. Constant-currency model: tariff escalation, inflation and financing structure are not modelled. Every number shown can be re-derived from the fields above with the formulas listed on this page.