Planning to invest in PV for your business? Invest intelligently and optimize your investment payback

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You are a medium-size business owner, a factory technical director, a hotel manager. You have been searching for opinions on how to install photovoltaic (PV) for your company on Google, you are getting offers from solar installers, you are determined to get the best price!

But if the two questions you constantly hear from solar installers are:

  • Send me the detailed parameters of your roof, and
  • Send me your monthly electricity bill

…then I have news for you – you will not make a good investment!

But how is that possible, surely you cannot fit more solar panels on your roof than the size of the roof allows, and you cannot change your electricity bill? Correct, the question about available roof size is an important one, but it is a technical question…and there are quite a few things you can do to reduce your electricity consumption.

Before we go into any further detail, let’s just establish what are the correct starting questions for this problem. These are economic questions – not technical ones – and they will help you get the best payback on your photovoltaic investment:

  • Before I install PV, is there a way to reduce my energy usage?

Why is this important? If you can reduce your energy usage, then you will have less energy to offset and will need a smaller PV system; so you will need to invest less capital.

  • How do I find the optimal match between my daily consumption profile and the production profile of a PV system?

Why is this important? An optimal profile match will ensure that as much as possible of the energy you consume in any given hour is produced by your PV system; this will result in the best payback for your investment.

How can I reduce energy usage

If you read our blog “Understand your electricity bill and make practical decisions how to cut energy cost”, then you already know that Energy Intelligence  can provide you with the tools to eliminate Energy Waste created by:

  • Old, inefficient or broken equipment
  • Running equipment unnecessarily – for example during the night or during the weekend
  • Inefficient lighting
  • Not having an energy management system that can identify and alert you to areas where energy is being wasted

Eliminating wasted energy from your business makes it more energy efficient and reduces your energy consumption, and thus reduces the size of your PV investment – a double bonus!

Find optimal match between energy consumption and PV production

You have all seen this chart from solar installer offers, it shows the production of your planned PV system. The installer then compares the PV production to your total monthly energy consumption, and tells you what your payback is. A perfectly reasonable calculation, right? Wrong!

This calculation has one fundamental flaw – it starts with the size of the PV system which can fit on your roof, without evaluating if such system is too large or too small for your energy consumption. Why is that important – read the examples below.

The tale of the correct 80 kWp photovoltaic system

Meet three businesses – a holiday resort, a manufacturing facility, and a packaging business. All three considered installing a photovoltaic system and started collecting offers from solar installers who estimated how many solar panels their roof can accommodate. But all three ended up in a very different place.

Example #1
The owner of a holiday villa resort got offers from a number of solar installers who repeatedly told him that he should be able to fit a solar system of 80 kWp on his premises, enough to offset his 80 kW of energy consumption. But when 3-D Energy created a digital energy map of the resort’s energy usage, a different picture emerged. First, the resort seldom consumed as much as 80 kW during any given day (See graph below). Second, the resort’s consumption showed consistent peaks around 08:00 (breakfast), 12:00 – 13:00 (lunch) and 18:00 – 19:00 (dinner preparation).

After analyzing the real-time consumption data, the owner concluded that the correct size PV system is actually 40 kWp, much better suited to meet the resort’s relatively constant energy usage during the day. In addition, 3-D Energy recommended that the resort install a battery to cut their consumption peaks. The result was an improvement of the owner’s payback of the PV investment by more than 2.5 years.

Example #2
A manufacturer had experienced nearly 50% cost increase in 2018, and was searching for solutions to take control of energy costs. The factory manager had heard about solar, and discussed offers with solar installers. As the factory roof could accommodate up to 165 kWp of solar modules, every installer suggested 165 kWp as the optimal technical solution.

3-D Energy took a different approach, targeting optimal economics for the factory. Data analytics was used to set up monitoring of key operational areas within the facility, which created a detailed understanding of the energy consumed by the factory in 60-second intervals. The data showed several areas for easy energy optimization – several machines needed maintenance and had abnormally high energy consumption, unnecessary equipment stayed on during the weekend creating sizeable energy usage. Fixing these inefficiencies reduced the factory’s energy usage by 4% on an annualized basis.

Next, 3-D Energy analyzed the optimal size of a PV system. Since the factory operates in 3 shifts during weekdays with a maximum consumption of ~ 100-110 kW (See graph below), the 165 kWp size proposed by solar installers was uneconomical. Moreover, given that the factory cannot benefit from solar production from 19:00 – 06:00 and does not work during the weekend, the owner elected to have a conservatively sized PV system of ~80 kWp that would cover energy demand consistently during the day.

A conservative approach to finding the optimal size PV system using Energy Intelligence vs. simply evaluating available rooftop space improved the owner’s investment payback by nearly 2 years.

Example #3
The owner of a packaging facility was increasingly concerned about rising electricity prices and was looking for long-term solutions. Over 30% increase during the past 12 months had put significant pressure on the business’ financial margins. The roof of the packaging facility could accommodate up to 150 kWp of solar modules. The owner, however, decided to first implement Energy Intelligence  in the facility before making a decision on optimal solar system size. A month-long detailed analytics of 60-second consumption data showed that the facility’s energy consumption profile aligns almost perfectly with the production profile of a PV system – from 07:00 to 19:00.

The data showed that the optimal PV system size should be ~75-80 kWp (See graph below). Once the appropriate size for self-consumption was decided, 3-D Energy helped the owner evaluate the economics of investing in additional 70 kWp of PV capacity to be sold to the grid, which requires additional permits from the interconnecting utility.

The final decision was a 150 kWp solar system – 80 kW is used to offset energy consumption, and ~70 kW is sold to the energy grid under a special permit. The two-step analysis produced an optimal result – offsetting as much energy consumption as practical, combined with generating extra revenue for the company to supplement its operations.


Investing in a photovoltaic system is a major investment decision for your company. If your priority is to fully utilize your available rooftop space, Energy Intelligence is of no help to you. But if your goal is to maximize the return on your investment, then simply using our platform can take you a long way towards that goal.

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