Diesel to solar savings calculator

How much could you save by switching to solar power?

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Why it matters

Islands pay the highest energy prices in the world. Solar changes that math.

2–8×higher
Cost of diesel electricity vs. mainland grids
Island utilities typically pay $0.40–$1.50/kWh for diesel generation - a structural cost that solar directly displaces.
1,800–2,400kWh/m²/yr
Solar irradiance in tropical island regions
Most island communities lie in high-irradiance zones - making floating solar viable at system sizes that produce real returns at real timescales.
2.68kg CO₂/L
CO₂ eliminated with every litre of diesel displaced
IPCC Tier 1 combustion factor for diesel. Each litre your island stops burning reduces both fuel cost and carbon output by this fixed amount.
IEC 61724-1 & IPCC AR6
Engineering parameters and emission factors used throughout
Indicative estimate only
Not a feasibility study - contact Reverlast for site-specific assessment
Solar potential
Population
Island selected
2
Your island's numbers
3
Estimate

Your island's numbers

Pre-filled where we have data - adjust any value to match your local reality.

These figures drive the estimate. The closer they are to your actual utility data, the more accurate your results will be.

We do not have pre-filled data for this location. Fill in the fields below with accurate local information - the more precise the data, the more accurate your savings estimate.

Location name
Population
residents
Tourism and industry can significantly increase energy needs above population-based estimates. Adjust daily consumption below if needed.
Total daily energy consumption
kWh / day
Delivered diesel price
$ / litre USD
Generator efficiency
editable
litres / kWh
Old / poorly maintained: ~0.35  ·  Average: ~0.31  ·  Modern efficient: ~0.27
Solar irradiance
Auto-filled · editable
kWh / m² / year
Diesel share of current grid
editable
% diesel
All diesel: 100% · Mixed grid (e.g. some wind): 60–80% · Mostly other sources: <50%
Diesel displacement target
75 %
20%60%100%
Population
kWh/m²/yr
Solar irradiance (GHI)
$/L
Delivered diesel cost
Solar share · diesel backup retained

Average annual saving: $

Total over 25 years: $

75% solar · 20-year plan · $/L delivered diesel

Illustrative model, not a feasibility study · based on IEC 61724-1 and IPCC AR6 parameters

System dimensions
MWp
Solar array
MWh
Battery storage

The floating solar array is sized to meet the island's energy needs. Battery storage is included at the Reverlast standard of 3 MWh per MWp, fully included in the PPA rate.

Floating modules
Average daily solar output MWh/day
Capacity factor · annual yield% · MWh/yr

Capacity factor and yield are based on satellite irradiance data at optimal tilt with single-axis tracking (+8% irradiance capture), multiplied by an 85% performance ratio (the 80% land-based IEC 61724-1 baseline, plus 8% bifacial pontoon-albedo and ocean-cooling gains, minus 3% salt-soiling losses).

Power purchase agreement
$
/kWh
Reverlast PPA rate · fixed for 25 years
Estimated current cost
$/kWh
Reverlast rate
$/kWh
No upfront capital · savings from day one

Due to reliance on imported diesel, electricity is estimated to cost around $/kWh. Under the PPA, the island pays Reverlast this fixed rate per kWh. Local distributors may add their own fees on top. Savings begin from day one with no upfront investment required.

Cost reduction vs. current cost
Island savings · cost of electricity over 25 years
$
Average annual savings · +3%/yr diesel price inflation
Adjust diesel cost:
$ /L
Reverlast (fixed)
Diesel · 0% cost inflation
Diesel · 3% per year cost inflation
Avg saving/yr · flat diesel
$
Avg saving/yr · +3% diesel
$
Total 25yr savings · +3%
$

The chart shows the cost of electricity per kWh over time. With Reverlast, that cost is fixed for the full duration of the agreement. The shaded area between the lines is the saving your community keeps. Use the diesel cost field above to explore different scenarios.

Year 1 savings$
Final year savings$
Total · flat diesel$
Total · +3%/yr diesel$
Energy mix: before vs. after Reverlast
Before
100% diesel
After

Diesel
Solar (Reverlast)

Solar handles base load and substantially reduces reliance on imported diesel. During prolonged cloudy weather or periods of peak demand, existing diesel generators provide backup power. Energy security is never compromised.

CO₂ avoided · Diesel displaced
tonnes CO₂ avoided/yr
Litres displaced/yr
% of current use

CO₂ is calculated using the IPCC Tier 1 factor of 2.68 kg per litre of diesel. Every litre replaced by solar is one fewer fuel shipment, reducing the community's exposure to global oil cost volatility.

CO₂ factor2.68 kg/L
Diesel price today$/L
Annual diesel cost$
Step 01 · System size

How big does the solar system need to be?

Daily energy × solar share ÷ (peak sun hours × effective performance (optimal tilt × tracking × 85% PR)) = system size in kWp

Solar irradiance (GHI, kWh/m²/yr) is sourced from NASA POWER satellite data for all locations, with Solargis values pre-loaded for known islands. Capacity factor (CF) is derived as: GHI × performance ratio ÷ 8,760 hours. The performance ratio for Reverlast floating systems is 85% (the 80% land-based IEC 61724-1 baseline, plus 8% bifacial pontoon-albedo and ocean-cooling gains, minus 3% salt-soiling losses). This CF, and the GHI source, can be reviewed in the system dimensions card above.

Step 02 · Fuel replaced

How many litres of diesel actually get replaced?

Solar energy generated per year ÷ 3.2 kWh per litre of diesel = litres no longer needed

Island diesel generators produce roughly 3.2 kWh for every litre burned - that's their typical conversion efficiency under real operating conditions. Each litre this system replaces is fuel that never needs to be ordered, shipped, stored, or handled.

Step 03 · PPA pricing

What will the island actually pay per kWh?

Total 25-year project cost ÷ total energy produced = per-kWh PPA rate

The PPA rate is derived from the full project cost (equipment, shipping, O&M, financing, and decommissioning after 25 years) spread across every kilowatt-hour the panels will ever generate. The result is a fixed cost per kWh that is lower than what the community currently pays for electricity, so savings begin from day one of the contract.

Step 04 · Carbon impact

How much CO₂ stops being emitted?

Litres of diesel avoided × 2.68 kg of CO₂ per litre ÷ 1,000 = tonnes eliminated per year

2.68 kg/L is the IPCC's published Tier 1 emission factor for diesel combustion - the same number national governments use when reporting to the UN. It's a conservative, universally accepted figure.

Step 05 · Battery storage

How much battery backup is included?

3 MWh per MWp installed (3-hour reserve)

Battery keeps the grid stable at night and during cloudy stretches. Reverlast uses a standard 3 MWh per MWp - enough for overnight coverage without over-building storage. This is the Reverlast platform standard, fully included in the PPA rate.

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Reverlast floating solar · based on IEC 61724-1 and IPCC AR6 parameters · illustrative model only