1. Copyright © 2015 A O’Leary
Case Study – Moshulu Export Management
Moshulu is a family run business started in 1974. The company import, distribute and sell colourful leather footwear
through around 40 stores and their online and catalogue business. Head office is based in Honiton in a 55,000sqft
warehouse and offices. Neal Fulls, the Financial Director, met with Source Renewable Ltd in 2014 to discuss their energy
requirements and, with an electricity bill of around £10,000/annum, Neal was keen to find ways of reducing their energy
costs. The company are planning growth and even looking at electric vehicles in the future, so their electricity
consumption is only going to increase over time. Together with rising electricity costs Neal could see that the ROI from
Solar PV was a very attractive proposition that would safeguard the company from being wholly dependent on their
current and future electricity suppliers.
With the level of grid saturation, from a micro-generation point of view, in the area, it was no particular surprise that the
DNO (Western Power Distribution) advised a limit on exported energy sent back to the grid. This export limitation was
stipulated to be no more than 30kW at any time.
Source Renewable was assigned the task of designing a suitable PV solution that provided sufficient yield to reduce the
site’s daily demand, and also meet the DNO’s requirements for limiting the amount of reverse energy sent back to the grid.
A 50kWp array was determined to be the ideal solution.
With system design and supply support provided by Sibert Solar, a 49.90kWp array using 260Wp REC solar PV modules,
Advanced Energy (AE) inverters, K2 Speedrail mounting kit and Sibert Solar’s EMS (Export Management System) power
management solution was installed, resulting in a system that takes full advantage of the customer’s location in South-
West England, but also provides compliance with the DNO’s requirements.
Projected yield is just under 49MWh/year with a normalised energy ratio of 979kWh/kWp and performance ratio of 91%.
System Overview:
Trapezoidal steel roof structure
192pcs REC260PE PV modules
K2 Speedrail mounting kit
AE Inverters – 2pcs 20kW 3phase, built-in Ethernet (AE SiteLink monitoring) & DC disconnector
Sibert Solar EMS Power Management, incorporating Solar-Log dynamic feed-in control with electro-mechanical
fail-safe.
System Function Overview:
1. PV array functions as normal, AE inverters are grid tied and feed local demand from the facility.
2. Solar-Log 2000 unit monitors generation and feed-in to the grid on a closed-loop basis, and dynamically controls
the output of the inverters (via RS485) according to the calculated consumption and prescribed export limit.
3. If the feed-in power exceeds the control limit then the electro-mechanical fail-safe backup system shuts down
one of the two inverters.

2. Copyright © 2015 A O’Leary
4. Reverse energy drops below threshold, triggering an off-delay timer that resets the system back to normal
working conditions.
5. If the fail-safe control system’s 24vdc supply bus fails, or the mains supply is lost, then the system reverts to fail-
safe mode accordingly.
6. Test & Reset functionality is built into the EMS solution from Sibert Solar
About Source Renewable:
Source Renewable is an award-winning, renewable energy business based in South Molton, Devon. We are experts in the
installation of renewable energy systems for domestic properties, businesses, organisations, and communities and offer a
full energy consultation process to provide tailored renewable energy solutions.
About Sibert Solar:
Sibert is a company firmly established in the design, development and manufacture of special purpose machinery as well as
the procurement and supply of key products to the renewable-energy manufacturing and installation sectors. Sibert began
as a family business in Surrey over 30 years ago.