Advisory brief · Sierra Leone
Sierra Leone is in the midst of a solar+storage revolution: companies in Freetown are increasingly eyeing the switch
Sierra Leone is in the midst of a solar+storage revolution: companies in Freetown are increasingly eyeing the switch
In Sierra Leone, commercial and industrial customers pay among the highest commercial electricity prices in West Africa. At the same time, the grid delivers among the least reliable supply in the region. This makes Sierra Leone a booming market for solar+storage systems. Ember estimates that the solar Sierra Leone installs in 2026 alone will add the equivalent of 97% of its annual grid electricity generation (1). In this analysis, we show how the number and the type of outages influence payback time for these installations and what businesses can do to go solar with ease.
In Sierra Leone, commercial and industrial customers pay among the highest commercial electricity prices in West Africa. At the same time, the grid delivers among the least reliable supply in the region. This makes Sierra Leone a booming market for solar+storage systems. Ember estimates that the solar Sierra Leone installs in 2026 alone will add the equivalent of 97% of its annual grid electricity generation (1). In this analysis, we show how the number and the type of outages influence payback time for these installations and what businesses can do to go solar with ease.
$0.28
Per kWh for a commercial customer on the EDSA T2 tariff
3,600
Outage hours a year in eastern Freetown (about 41% of the year)
2.1 yrs
Payback on solar alone, before any storage is considered
For this short brief, we analyzed a mid-size hotel as a useful test case. A hotel runs through the day and into the evening, its air conditioning represents a major source of power demand, and outages have a direct influence on guest experience. Also, like hospitals and other vital infrastructure in the country, most hotels already own their own generator and are painfully aware of what running it costs.
For this short brief, we analyzed a mid-size hotel as a useful test case. A hotel runs through the day and into the evening, its air conditioning represents a major source of power demand, and outages have a direct influence on guest experience. Also, like hospitals and other vital infrastructure in the country, most hotels already own their own generator and are painfully aware of what running it costs.
Setting the stage
Setting the stage
Setting the stage
The hotel load curve is based on the load curve of a real-life hotel, adjusted for the size and for the weather conditions in Sierra Leone. The hotel modeled here uses 346 MWh a year in electricity and peaks at 81 kW. Its load curve is measured half-hourly across twelve months, and the system is modeled over twenty-five years, including battery replacements.
The load curve is shown in Figure 1. Demand climbs steeply from six in the morning, as guests wake up, breakfast service is started and the first air-conditioning ramp arrives. The curve holds through the working day and falls away late. On the other hand, solar output shows a much more gradual and evenly spread output curve. Compared to the load curve, it arrives after the morning peak has already passed, and stops before the evening one begins.
The hotel load curve is based on the load curve of a real-life hotel, adjusted for the size and for the weather conditions in Sierra Leone. The hotel modeled here uses 346 MWh a year in electricity and peaks at 81 kW. Its load curve is measured half-hourly across twelve months, and the system is modeled over twenty-five years, including battery replacements.
The load curve is shown in Figure 1. Demand climbs steeply from six in the morning, as guests wake up, breakfast service is started and the first air-conditioning ramp arrives. The curve holds through the working day and falls away late. On the other hand, solar output shows a much more gradual and evenly spread output curve. Compared to the load curve, it arrives after the morning peak has already passed, and stops before the evening one begins.
Figure 1. A mid-sized Freetown hotel’s demand across an average day, with the output of a 100 kW solar array
Kilowatts, averaged across the year, by half hour
Demand is a measured half-hourly profile. Solar is PVGIS SARAH2, 2015–2020 averages for Freetown (2).
This gap between the load curve and solar output is exactly where batteries can potentially add a lot of value. Especially when the battery is used as back-up.
This gap between the load curve and solar output is exactly where batteries can potentially add a lot of value. Especially when the battery is used as back-up.
Grid failures follow a seasonal pattern, which can influence system dimensioning
Grid failures follow a seasonal pattern, which can influence system dimensioning
Grid failures follow a seasonal pattern, which can influence system dimensioning
About half of Sierra Leone’s electricity is generated from hydropower (3). Bumbuna, the largest plant, is rated at 50 MW but drops to a fifth of that in February as water flow declines (3, 4). Supply is deeply seasonal, leading to a stretch of dry months from December to April in most years. Fortunately for business owners, those are also the sunniest months, which means that this seasonal pattern works firmly in a solar buyer’s favour.
The reliability evidence tells the tale: researchers in Sierra Leone installed sensors in 48 businesses across 12 transformers in Freetown and recorded every interruption over a period of nine months. In total, 6,195 outages were recorded (5). And some parts of the city were hit far harder than others: businesses in eastern Freetown averaged 300 outage hours a month, nearly seven times more often than those in the west.
About half of Sierra Leone’s electricity is generated from hydropower (3). Bumbuna, the largest plant, is rated at 50 MW but drops to a fifth of that in February as water flow declines (3, 4). Supply is deeply seasonal, leading to a stretch of dry months from December to April in most years. Fortunately for business owners, those are also the sunniest months, which means that this seasonal pattern works firmly in a solar buyer’s favour.
The reliability evidence tells the tale: researchers in Sierra Leone installed sensors in 48 businesses across 12 transformers in Freetown and recorded every interruption over a period of nine months. In total, 6,195 outages were recorded (5). And some parts of the city were hit far harder than others: businesses in eastern Freetown averaged 300 outage hours a month, nearly seven times more often than those in the west.
Figure 2. Hours without grid power each month, for the East and West of Freetown.
Stretching that monthly average to yearly outage figures, that is roughly 3,600 hours a year of outages in the east versus 1,278 hours in the west. And yet, two businesses a few kilometres apart pay the same tariff for the same product and receive a service that is markedly less reliable. Since businesses in the high-outage regions are forced to rely on back-up generators more often, the economics of investing in solar+storage differ significantly depending on where a particular business is located. The frequency of outages also impacts how large the battery system in particular should be to cover the gaps.
Stretching that monthly average to yearly outage figures, that is roughly 3,600 hours a year of outages in the east versus 1,278 hours in the west. And yet, two businesses a few kilometres apart pay the same tariff for the same product and receive a service that is markedly less reliable. Since businesses in the high-outage regions are forced to rely on back-up generators more often, the economics of investing in solar+storage differ significantly depending on where a particular business is located. The frequency of outages also impacts how large the battery system in particular should be to cover the gaps.
Modeling the complex reality on the ground
Modeling the complex reality on the ground
Modeling the complex reality on the ground
Sierra Leone represents a solar+storage market thinner than other larger African countries such as Nigeria and South Africa. Overall market volumes are lower, which results in less competition and likely translates into higher profit margins for importers and retailers. Scarcity of skilled technical workers adds another layer to this premium. As a result, equipment is priced at $585 per kWp of solar and $234 per kWh of storage, a 30% premium over what the same hardware costs in larger markets like Nigeria or South Africa.
Sierra Leone’s tax breaks for solar are narrower than often assumed: the Finance Act 2026 removes import duty only on panels under 300 W and solar home system parts, and exempts solar mini-grid power from GST (6). Commercial-scale systems are not explicitly covered.
Sierra Leone represents a solar+storage market thinner than other larger African countries such as Nigeria and South Africa. Overall market volumes are lower, which results in less competition and likely translates into higher profit margins for importers and retailers. Scarcity of skilled technical workers adds another layer to this premium. As a result, equipment is priced at $585 per kWp of solar and $234 per kWh of storage, a 30% premium over what the same hardware costs in larger markets like Nigeria or South Africa.
Sierra Leone’s tax breaks for solar are narrower than often assumed: the Finance Act 2026 removes import duty only on panels under 300 W and solar home system parts, and exempts solar mini-grid power from GST (6). Commercial-scale systems are not explicitly covered.
Figure 3. Main assumptions.
| Input | Value | Basis |
|---|---|---|
| Electricity tariff | $0.276/kWh | NLe 6.338 (SLL 6,338 in old leones), T2 Commercial including GST (7) |
| Diesel alternative | $0.65/kWh | NLe 45.00 a litre as of 14 September 2026 (8), at an estimated 3 kWh a litre; fuel only |
| Solar capex | $585/kWp | E3Applied estimate: regional basis plus a 30% Sierra Leone premium |
| Battery capex | $234/kWh | Same premium; above the utility-scale floor (9) |
| Discount rate | 17% | Bank of Sierra Leone policy rate, June 2026 (10) |
| Site demand | 346 MWh/yr | 81 kW peak, measured half-hourly hotel profile |
The results: solar always pays, storage sizing depends on how extreme the outages are
The results: solar always pays, storage sizing depends on how extreme the outages are
The results: solar always pays, storage sizing depends on how extreme the outages are
Installing solar panels as a commercial or industrial business in Sierra Leone is a clear financial winner. Assuming all the solar power can be consumed onsite, a 100 kW array with no storage at all has a net present value of $229,117 over twenty-five years even if the grid never fails once, and $473,936 in eastern Freetown where outages are more frequent. The payback time ranges from 2.06 to 2.95 years depending on the assumptions made about the frequency of grid outages. When rightly sized, there is no conceivable future in which investing in solar becomes a bad financial decision.
Installing solar panels as a commercial or industrial business in Sierra Leone is a clear financial winner. Assuming all the solar power can be consumed onsite, a 100 kW array with no storage at all has a net present value of $229,117 over twenty-five years even if the grid never fails once, and $473,936 in eastern Freetown where outages are more frequent. The payback time ranges from 2.06 to 2.95 years depending on the assumptions made about the frequency of grid outages. When rightly sized, there is no conceivable future in which investing in solar becomes a bad financial decision.
The real challenge in Sierra Leone becomes how large to dimension the battery. Ultimately, the value of the battery depends on something that remains outside the buyer’s control, namely, the frequency and duration of power outages. Since the future is unknown, households and C&I customers have to weigh several tradeoffs when it comes to battery sizing.
Making matters harder to predict is the fact that outages are highly seasonal, and increasingly affected by unreliable rainfall patterns, which are in turn affected by a growing risk of drought due to climate change.
Against this backdrop, a battery provides a major hedge, one that protects against a growing hydrological risk on one hand, and on growing geopolitical and fuel price risks on the other.
The real challenge in Sierra Leone becomes how large to dimension the battery. Ultimately, the value of the battery depends on something that remains outside the buyer’s control, namely, the frequency and duration of power outages. Since the future is unknown, households and C&I customers have to weigh several tradeoffs when it comes to battery sizing.
Making matters harder to predict is the fact that outages are highly seasonal, and increasingly affected by unreliable rainfall patterns, which are in turn affected by a growing risk of drought due to climate change.
Against this backdrop, a battery provides a major hedge, one that protects against a growing hydrological risk on one hand, and on growing geopolitical and fuel price risks on the other.
Figure 4. Net present value, payback and outage cover for four solar and battery systems, under three levels of grid reliability
| System | Capex | No outages0 outage h/yr | Western Freetown1,278 outage h/yr | Eastern Freetown3,600 outage h/yr | |||||
|---|---|---|---|---|---|---|---|---|---|
| NPV | Payback | NPV | Payback | Cover | NPV | Payback | Cover | ||
| 1Solar only100 kW solar | $58k | $229k | 3.0 | $300k | 2.6 | 32% | $474k | 2.1 | 37% |
| 2Solar + small battery100 kW solar + 150 kWh battery | $94k | $177k | 4.1 | $308k | 3.1 | 59% | $517k | 2.4 | 50% |
| 3Larger solar + battery300 kW solar + 350 kWh battery | $257k | $101k | 6.6 | $326k | 4.8 | 92% | $762k | 3.3 | 88% |
| 4Full outage cover300 kW solar + 700 kWh battery | $339k | -$21k | 9.9 | $226k | 5.8 | 100% | $741k | 3.8 | 100% |
Highest NPV for that grid. NPV and capex in US dollars; payback in years.
NPV is the value of after-tax savings over 25 years of operation, net of all costs, at 30% corporate tax (6), discounted at 17% (10) and assuming an all-equity purchase. Savings combine grid electricity displaced at the T2 tariff (7) with diesel avoided during outages (8). Payback is simple (undiscounted) and counted from the start of a one-year construction period. Cover is the share of electricity demand during outage hours met by the system. The battery is replaced whenever its capacity falls to 80%, in years 8, 15 and 22, each time at 30% of the original battery cost. Inverter replacement is not modelled.
These four cases point to several conclusions:
First, a C&I customer facing relatively low outage levels, and that expects this to remain the case, is likely best served by a modest solar system. Panels alone (system 1 in Figure 4) have a positive net present value of $229,000 even if the grid never fails again: adding 150 kWh of storage (system 2) in this case results in a lower NPV overall.
By contrast, if the customer expects the grid to remain as unreliable as it is (on average), or get worse, the situation changes dramatically in favor of scaling up the size of both solar and storage systems on site: tripling the solar system size and adding 350 kWh of battery storage (system 3) lifts the eastern Freetown NPV from $474,000 to $762,000 and enables the customer to meet up to 88% of total outage-related demand.
The last step, full outage cover (system 4), costs less than it looks in eastern Freetown. Another $82,000 of capital takes cover from 88% to 100% and lowers NPV by only $22,000. In western Freetown, the same step costs $100,000 of NPV.
These four cases point to several conclusions:
First, a C&I customer facing relatively low outage levels, and that expects this to remain the case, is likely best served by a modest solar system. Panels alone (system 1 in Figure 4) have a positive net present value of $229,000 even if the grid never fails again: adding 150 kWh of storage (system 2) in this case results in a lower NPV overall.
By contrast, if the customer expects the grid to remain as unreliable as it is (on average), or get worse, the situation changes dramatically in favor of scaling up the size of both solar and storage systems on site: tripling the solar system size and adding 350 kWh of battery storage (system 3) lifts the eastern Freetown NPV from $474,000 to $762,000 and enables the customer to meet up to 88% of total outage-related demand.
The last step, full outage cover (system 4), costs less than it looks in eastern Freetown. Another $82,000 of capital takes cover from 88% to 100% and lowers NPV by only $22,000. In western Freetown, the same step costs $100,000 of NPV.
The point at which storage starts paying
The point at which storage starts paying
The point at which storage starts paying
Three scenarios give three points, and a real site sits somewhere between them. Holding the system fixed and sweeping the outage calendar turns those points into a threshold, so a business can locate itself on it.
Three scenarios give three points, and a real site sits somewhere between them. Holding the system fixed and sweeping the outage calendar turns those points into a threshold, so a business can locate itself on it.
Figure 5. What a 150 kWh battery adds to net present value, against annual outage hours.
Below 893 hours the battery loses money under any outage pattern. Above 1,514 it pays under all of them.
Below 893 outage hours a year, a 150 kWh battery loses money whatever shape the outages take. Above 1,514 hours it pays for itself under every pattern tested. Between those two figures the answer depends on how the outages arrive. Many short interruptions are easy to ride through, so the battery starts paying at 893 hours when outages average six hours each. A handful of very long ones drain any pack this size, pushing the threshold up to 1,514 hours when they average fourteen. Two hotels can lose the same number of hours in a year and land on opposite sides of the decision.
Western Freetown sits at 1,278 hours, inside that range, which is why storage there is a real question rather than an obvious yes. Eastern Freetown at 3,600 hours is far past it, and businesses there would most likely benefit from a storage system accompanying their solar array.
Below 893 outage hours a year, a 150 kWh battery loses money whatever shape the outages take. Above 1,514 hours it pays for itself under every pattern tested. Between those two figures the answer depends on how the outages arrive. Many short interruptions are easy to ride through, so the battery starts paying at 893 hours when outages average six hours each. A handful of very long ones drain any pack this size, pushing the threshold up to 1,514 hours when they average fourteen. Two hotels can lose the same number of hours in a year and land on opposite sides of the decision.
Western Freetown sits at 1,278 hours, inside that range, which is why storage there is a real question rather than an obvious yes. Eastern Freetown at 3,600 hours is far past it, and businesses there would most likely benefit from a storage system accompanying their solar array.
What this means for a solar+storage buyer
What this means for a solar+storage buyer
What this means for a solar+storage buyer
The take-home message is clear: solar stands on its merits today, and should be sized in relation to the total power bill and fuel price expenditure; it does not depend on any forecast about future reliability. Installing solar to self-supply part of one’s electricity needs makes solid economic and business sense in Freetown, Sierra Leone, as it does in many other jurisdictions across Africa.
In a region with unreliable power supply, how exactly to dimension your storage becomes one of the critical decision points, as increasing the size of the storage system significantly drives up the total Capex. Based on our analysis, carefully sizing the storage system for typical C&I customers can easily represent tens of thousands of dollars over the system’s life in value created, or destroyed.
Most businesses lack the data necessary to make a balanced investment decision. For a business weighing a six-figure investment, waiting a few weeks to a month to obtain independent analysis from someone other than the vendor/EPC company installing the system can help companies avoid costly mistakes, and steer clear of over-investment.
The take-home message is clear: solar stands on its merits today, and should be sized in relation to the total power bill and fuel price expenditure; it does not depend on any forecast about future reliability. Installing solar to self-supply part of one’s electricity needs makes solid economic and business sense in Freetown, Sierra Leone, as it does in many other jurisdictions across Africa.
In a region with unreliable power supply, how exactly to dimension your storage becomes one of the critical decision points, as increasing the size of the storage system significantly drives up the total Capex. Based on our analysis, carefully sizing the storage system for typical C&I customers can easily represent tens of thousands of dollars over the system’s life in value created, or destroyed.
Most businesses lack the data necessary to make a balanced investment decision. For a business weighing a six-figure investment, waiting a few weeks to a month to obtain independent analysis from someone other than the vendor/EPC company installing the system can help companies avoid costly mistakes, and steer clear of over-investment.
Conclusion
Conclusion
Conclusion
Sierra Leone experiences among the worst grid reliability in the region. In addition, electricity tariffs are relatively high, along with the diesel and gasoline frequently used as back-up.
Making a smart, well-sized investment in a solar-plus-storage system can save companies money while providing a clean and quiet way to keep the lights on. The weaker the grid reliability, the shorter the payback.
Sierra Leone experiences among the worst grid reliability in the region. In addition, electricity tariffs are relatively high, along with the diesel and gasoline frequently used as back-up.
Making a smart, well-sized investment in a solar-plus-storage system can save companies money while providing a clean and quiet way to keep the lights on. The weaker the grid reliability, the shorter the payback.
Sources
Sources
Sources
1. Solar installation outlook. Ember, Africa is on track for a record year of solar installations in 2026, up 45% year-on-year, driven largely by distributed solar (26 August 2026). New solar installed in Sierra Leone in 2026 is estimated to add the equivalent of 97% of annual grid electricity generation, the highest share of the African countries listed. https://ember-energy.org/latest-updates/africa-is-on-track-for-a-record-year-of-solar-installations-in-2026-up-45-year-on-year-driven-largely-by-distributed-solar/
2. Solar resource. European Commission Joint Research Centre, PVGIS 5.2, PVGIS-SARAH2 hourly irradiation for Freetown, 2015-2020. https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis/pvgis-releases/pvgis-52_en
3. Hydropower share and seasonality. International Tracking Standard Foundation, Country Assessment Report: Sierra Leone (April 2025). About half of the country’s electricity is generated from hydroelectric sources, per the Ministry of Energy; installed capacity was slightly over 300 MW in 2023, of which Bumbuna is a seasonal 50 MW, and dry-season hydro output falls to 20-25% of capacity. Thermal plants make the second-largest contribution: KingTom 10 MW, Blackhall Road 16.5 MW and the Karpowership vessel 50 MW, among others. https://www.trackingstandard.org/wp-content/uploads/ITSF_CountryAssessmentReport_Sierra-Leone_EPP_v1.0_2025_PUBLIC.pdf
4. Supply position and Bumbuna dry-season output. Sierraloaded, EDSA load shedding in Freetown (10 March 2025). EDSA meets about 65% of Western Area demand, and announced load shedding for the Western Area as the dry season cut Bumbuna to under a quarter of peak production, undertaking that no customer would be without power for more than 72 consecutive hours without official fault notification. https://sierraloaded.sl/news/edsa-load-shedding-electricity-freetown/
5. Outage measurement, eastern vs western Freetown. Osunmuyiwa, O. & Klugman, N., Could improving power quality boost economic growth in Sierra Leone?, International Growth Centre (1 December 2025). nLine GridWatch wall-outlet sensors on 48 businesses across 12 transformers in Freetown, November 2024 to July 2025; 6,195 outage interruptions recorded. Eastern Freetown averaged 300 outage hours a month, nearly seven times western Freetown; 6-11 hours a day against 2-5 in May 2025. https://www.theigc.org/blogs/power-quality-economic-growth-sierra-leone
6. Tax and customs. Government of Sierra Leone, The Finance Act, 2026 (Act No. 1 of 2026), in force 1 January 2026. Corporate income tax raised from 25% to 30%; 0% import duty on solar panels under 300 W and on solar home system parts; GST exemption for renewable energy from solar mini-grids and for solar home systems. http://webtestcms.nra.gov.sl/uploads/The_Finance_Act_2026_121df05d9b.pdf
7. Electricity tariff. Sierra Leone Electricity and Water Regulatory Commission (EWRC), approved tariff for EDSA effective 1 October 2023. T2 Commercial SLL 5,511/kWh excluding GST and SLL 6,338/kWh including GST, in old leones (NLe 5.511 and NLe 6.338 after redenomination). https://ewrc.gov.sl/wp-content/uploads/2025/02/Approval-for-Gazette-1.pdf
8. Diesel pump price. GlobalPetrolPrices, Sierra Leone diesel prices. NLe 45.00 per litre as of 14 September 2026, up from NLe 40.00 a month earlier; 64% above a year earlier and about 41% above the world average. https://www.globalpetrolprices.com/Sierra-Leone/diesel_prices/
9. Battery capex benchmark. Ember, How cheap is battery storage? (December 2025). All-in utility-scale BESS capex around $125/kWh as of October 2025 outside China and the United States, the floor a C&I pack sits above. https://ember-energy.org/latest-insights/how-cheap-is-battery-storage/
10. Policy rate and inflation. Bank of Sierra Leone, Monetary Policy Statement, June 2026. Monetary Policy Rate raised 25bps to 17.00% at the Monetary Policy Committee meeting of 12 June 2026; headline inflation 10.83% in April 2026. https://bsl.gov.sl/Monetary%20Policy%20Statement%20-%20June%202026.pdf
11. Outage timing. Energy for Growth Hub, 160 days in the dark: understanding electricity unreliability in Nigeria (26 February 2025). Outage data from a city in southwestern Nigeria: outages ‘occur throughout the day and week’, with ‘limited patterns, such as peaks at 5 a.m. and 7 p.m.’; roughly 60% load shedding, over 30% forced. https://energyforgrowth.org/article/160-days-in-the-dark-understanding-electricity-unreliability-in-nigeria/
1. Solar installation outlook. Ember, Africa is on track for a record year of solar installations in 2026, up 45% year-on-year, driven largely by distributed solar (26 August 2026). New solar installed in Sierra Leone in 2026 is estimated to add the equivalent of 97% of annual grid electricity generation, the highest share of the African countries listed. https://ember-energy.org/latest-updates/africa-is-on-track-for-a-record-year-of-solar-installations-in-2026-up-45-year-on-year-driven-largely-by-distributed-solar/
2. Solar resource. European Commission Joint Research Centre, PVGIS 5.2, PVGIS-SARAH2 hourly irradiation for Freetown, 2015-2020. https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis/pvgis-releases/pvgis-52_en
3. Hydropower share and seasonality. International Tracking Standard Foundation, Country Assessment Report: Sierra Leone (April 2025). About half of the country’s electricity is generated from hydroelectric sources, per the Ministry of Energy; installed capacity was slightly over 300 MW in 2023, of which Bumbuna is a seasonal 50 MW, and dry-season hydro output falls to 20-25% of capacity. Thermal plants make the second-largest contribution: KingTom 10 MW, Blackhall Road 16.5 MW and the Karpowership vessel 50 MW, among others. https://www.trackingstandard.org/wp-content/uploads/ITSF_CountryAssessmentReport_Sierra-Leone_EPP_v1.0_2025_PUBLIC.pdf
4. Supply position and Bumbuna dry-season output. Sierraloaded, EDSA load shedding in Freetown (10 March 2025). EDSA meets about 65% of Western Area demand, and announced load shedding for the Western Area as the dry season cut Bumbuna to under a quarter of peak production, undertaking that no customer would be without power for more than 72 consecutive hours without official fault notification. https://sierraloaded.sl/news/edsa-load-shedding-electricity-freetown/
5. Outage measurement, eastern vs western Freetown. Osunmuyiwa, O. & Klugman, N., Could improving power quality boost economic growth in Sierra Leone?, International Growth Centre (1 December 2025). nLine GridWatch wall-outlet sensors on 48 businesses across 12 transformers in Freetown, November 2024 to July 2025; 6,195 outage interruptions recorded. Eastern Freetown averaged 300 outage hours a month, nearly seven times western Freetown; 6-11 hours a day against 2-5 in May 2025. https://www.theigc.org/blogs/power-quality-economic-growth-sierra-leone
6. Tax and customs. Government of Sierra Leone, The Finance Act, 2026 (Act No. 1 of 2026), in force 1 January 2026. Corporate income tax raised from 25% to 30%; 0% import duty on solar panels under 300 W and on solar home system parts; GST exemption for renewable energy from solar mini-grids and for solar home systems. http://webtestcms.nra.gov.sl/uploads/The_Finance_Act_2026_121df05d9b.pdf
7. Electricity tariff. Sierra Leone Electricity and Water Regulatory Commission (EWRC), approved tariff for EDSA effective 1 October 2023. T2 Commercial SLL 5,511/kWh excluding GST and SLL 6,338/kWh including GST, in old leones (NLe 5.511 and NLe 6.338 after redenomination). https://ewrc.gov.sl/wp-content/uploads/2025/02/Approval-for-Gazette-1.pdf
8. Diesel pump price. GlobalPetrolPrices, Sierra Leone diesel prices. NLe 45.00 per litre as of 14 September 2026, up from NLe 40.00 a month earlier; 64% above a year earlier and about 41% above the world average. https://www.globalpetrolprices.com/Sierra-Leone/diesel_prices/
9. Battery capex benchmark. Ember, How cheap is battery storage? (December 2025). All-in utility-scale BESS capex around $125/kWh as of October 2025 outside China and the United States, the floor a C&I pack sits above. https://ember-energy.org/latest-insights/how-cheap-is-battery-storage/
10. Policy rate and inflation. Bank of Sierra Leone, Monetary Policy Statement, June 2026. Monetary Policy Rate raised 25bps to 17.00% at the Monetary Policy Committee meeting of 12 June 2026; headline inflation 10.83% in April 2026. https://bsl.gov.sl/Monetary%20Policy%20Statement%20-%20June%202026.pdf
11. Outage timing. Energy for Growth Hub, 160 days in the dark: understanding electricity unreliability in Nigeria (26 February 2025). Outage data from a city in southwestern Nigeria: outages ‘occur throughout the day and week’, with ‘limited patterns, such as peaks at 5 a.m. and 7 p.m.’; roughly 60% load shedding, over 30% forced. https://energyforgrowth.org/article/160-days-in-the-dark-understanding-electricity-unreliability-in-nigeria/
Results are illustrative: the load curve is a representative hotel profile and the outage calendar is synthetic, matched to measured totals rather than replayed from the sensor record. Outages are weighted towards the evening, which is conservative for solar: evidence from elsewhere in the region shows outages occurring throughout the day (11). The main inputs and their sources are listed in Figure 3.