Energy Backup: Technical Considerations for Business Planning & Sales

Overview

Selling and installing a standalone battery system, like LightReach's Energy Backup lease, comes with some unique technical considerations. Ideally, many of these should be considered at point of sale. The goal of these guidelines is to help:

Maximize the value and benefits of customers NEW Energy Backup system
Maintain compatibility with any existing onsite equipment, while also maximizing the benefits of pairing any onsite solar with new storage
Adhere to all jurisdictional, utility, and manufacturer requirements.

An effective sale will consider the following:

1	Sizing (Battery Count)	Adhere to any size requirements from the battery manufacturer, especially for any Battery -> PV size limitations
2	Compatibility with Existing Solar	Select a battery manufacturer and configuration that is compatible with onsite equipment Capture any clear compatibility challenges that may prevent optimal experience - e.g. solar charging during backup not likely
3	Equipment Location	Couple battery equipment location with existing electrical and PV equipment as feasible and acceptable to customer All Energy Backup systems must include new equipment and unique monitoring. Repurposing any existing combiner/ controller equipment is NOT permitted.
4	Backup Functionality & Expectations	Select a battery quantity that helps support customers Energy Backup goals Clarify when whole home backup vs. partial backup is the be expected AND understand any musts for the customer on critical protected loads Discuss length of backup goals and backup expectations with customer
5	Energy Arbitrage and Optimization Benefits	For applicable markets, discuss the potential for a battery system helping to optimize customers energy use and utility rates Do NOT position Energy Backup system as "net savings" opportunity; Rather, it is likely that any utility bill savings will help offset some of the customers costs for Energy Backup

Sizing

Please reference all manufacturer documentation for sizing rules and requirements. These guidelines are intended as a summary guide only and do not override any manufacturer specific rules.

Sizing and compatibility will be confirmed at the Install milestone and will need to be corrected if not to manufacturer specifications.

Max allowable PV Size (kW AC) per Battery model:

Tesla Powerwall 3

Equipment	MAX Existing AC PV (kW)
One PW3	7.68
One PW3 + One Expansion	10.0
Two PW3	15.36
Two PW3 + One Expansion	17.68
Three PW3	23.04

Maximum total battery equipment on the same gateway is 4 PW3 + 3 Expansion units. Max existing PV sizing is 33.04 kW AC per gateway.

Further detail from Tesla: HERE

Enphase IQ Battery 10C:

Equipment	MAX Existing AC PV (kW)
One 10C	7.08
Two 10C	14.16
Three 10C	15.36
Four 10C	15.36

!MAXIMUM PV Sizing 15.36 kW AC even if 3+ batteries!

Example:

Existing PV 10kW AC - Two 10C batteries are required.

Existing Solar Compatibility

All batteries sold and installed through the Energy Backup lease must be compatible with any existing onsite solar equipment. New batteries must not interfere with proper function and performance of the customers existing solar and vice-versa.

The LightReach team has prepared the following notes and guidance as a support reference. This is not exhaustive and is intended as a DIRECTIONAL GUIDE ONLY

	Tesla Powerwall 3 (RECOMMENDED)	Enphase IQ Battery 10C (RECOMMENDED)
General	Flexible option for retrofitting with existing PV onsite	Flexible option for retrofitting with existing PV onsite
Compatible Solar Inverters	Most OEM’s and models	Most OEM’s and models pending software update expected by Sept 2025
Solar Backup Charging	Yes*	Yes* pending software update expected by Nov 2025
Compatible with no solar onsite	Yes	Yes

* onsite conditions may prevent this for limited exception cases

Note: This information is intended to support initial pilot program sales and business planning . Further corresponding detail will be published in the corresponding Operations knowledge base resources.

FAQs

1	What additional work scope (aka adders) can be included in the lease system price?	Any work required to enable the battery install and to meet local requirements is eligible to be included in the system price. This includes items such as electrical upgrades, trenching, installation of a concrete pad for battery mounting, or other related site preparation work. There are no specific adder fields or premiums included in our pricing sheets for approved work. While such work is not prohibited, there are no special pricing accommodations for them. Installers are permitted to execute work as necessary, within the confines of our existing pricing sheets.
2	What adders cannot be included?	Reroofs or any other work not related to the direct install of the battery cannot be included.
3	Is there a minimum or maximum system size or price?	The maximum system price for the total project with our Energy Backup program is $75,000. There is also a maximum system price for each battery manufacturer and quantity combination. This will also be visible when creating a quote: Enphase: max $20,000 per single battery Tesla: max $25,000 per single battery These maximums are designed to provide generous leeway to the EPC while providing competitive pricing constraints for homeowners. All Energy Backup systems must include a minimum of 10 kWh of storage capacity.
4	Is there a Domestic Content program?	No. In the Energy Backup program, there is not a Domestic Content “bonus” for pricing whereby installers are paid a higher amount for installing domestic material. Items such as higher pricing for domestic parts can be factored into the system price when creating a quote