Case study: solar and battery solutions for farmers

Client success story – Off-grid resilience and cost savings

Nesa’s journey in renewable energy began in 2015, when we installed a grid-tied solar system for one of South Africa’s most trusted tool and machinery brands. Years later, the same client approached us to help reduce the energy risk on their remote farm-where unreliable grid infrastructure and high diesel consumption posed serious operational and financial challenges.

The challenge: Energy risk in remote agriculture

Located in a remote area with frequent grid failures, the farm often relied on a 600kVA diesel generator to power critical operations. This not only incurred significant fuel costs, but also introduced a risk of catastrophic crop loss should both the grid and generator fail at the same time.

The Solution: Tailored micro-grid with solar, battery & generator integration

Using consumption data from the grid provider and our own meter loggers, our engineering team designed a robust hybrid energy system:

278kWp/220kWac Ground-Mounted Solar PV System (Fixed tilt)
500kW / 645kWh Battery Energy Storage System (BESS)
Full Generator Integration
Grid-Tied and Battery Inverters
Containerised Infrastructure for Batteries and Inverters

This design enables three key outcomes:

Daytime Load Support – Solar power supplements daytime energy needs.
Layered Backup – Batteries provide resilience and reduce dependency on the diesel genset.
Cost Savings – Solar and battery arbitrage reduce diesel usage and grid reliance.

Smart operation & energy arbitrage

The battery system is configured to discharge strategically during Peak grid tariff periods—reducing costs while maintaining a reserve charge to cover up to 2 hours of grid outage. During extended overcast periods, if both solar and grid are unavailable, the generator automatically recharges the batteries. This ensures uninterrupted power to critical systems.

We always recommend retaining a generator as a final layer of backup in agricultural settings.

Designed for future growth

Understanding the evolving nature of farming operations, the system was designed with scalability in mind. The containerised infrastructure allows space for additional battery capacity up to 1290kWh, while the PV ground mount can be expanded as demand increases.

Results: Energy independence, cost savings & peace of mind

As mentioned, the system is setup to Arbitrage and take full advantage of the batteries by charging during the day when there is excess solar available or during off-peak time periods when the cost per kWh is as low as R1.15. Then discharge during the morning and evening peaks when the cost per kWh can be as high as R6.90.

A portion of the batteries are retained above the recommended minimum level to allow for some backup in the event of an outage. The portion set aside for backup can be adjusted at any time should the client require it.

The graph below shows the impact of the solar and battery system on the client’s load (kW).

By reducing the load during peak time and spreading it across a 24-hour day the strain on aging Eskom infrastructure is reduced.

Since commissioning, the client has benefited from:

Reduced energy costs
Increased operational reliability
Improved energy independence

Our monitoring team continues to analyse real-time system performance and has already identified additional opportunities for cost optimisation, including energy banking with Eskom during low-usage seasons.

As the farming operation evolves, so too will the energy solution—ensuring long-term sustainability and profitability.

Project Performance Overview

Solar PV System Summary

Agreement Type	Outright Purchase
1st Year Solar Savings	R800,000
Payback Period	4–5 years
20-Year IRR	23%
20-Year NPV	R4.4 million
20-Year Savings	R26 million