Case study

19 kW off-grid solar and battery system in the Derwent Valley

A Derwent Valley home running fully off the grid, with 19 kW of LONGi solar and 45 kWh of usable Sigenergy battery storage, designed and installed by REST Energy.

Rated 5 out of 5

5.0 on Google · SAA accredited · 15+ years in renewable energy

5.0 on Google

SAA accredited

Accreditation S6285129

15+ years

in the renewable energy industry

7-year install warranty

installation warranty on our workmanship

Tasmanian owned

Local people, local knowledge

REST Energy installing an off-grid solar system on a home in the Derwent Valley, Tasmania

The project

This bespoke home in the Derwent Valley is a beautiful build that sits about 12 metres off the ground. Because of that height, REST worked to the builder's spec and installed the panels early while the scaffolding was still up.

George from REST Energy on the Derwent Valley build

19 kWDC solar system (STC)

23,818 kWhEstimated annual production

45.2 kWhBattery (45 kWh usable)

87%System efficiency

Why Sigenergy for this home

REST doesn't use the same equipment on every off-grid job. Quite often it uses Victron with copper-wound, transformer-based inverters, but this domestic home has a mix of induction and resistive loads. That includes hot water cylinders, lighting and power, an air fryer, a Thermomix, TVs, a fridge and a freezer. The Sigenergy 12 kW system runs all of these easily. The design started with the customer's loads, needs and expectations, which also decide how many batteries are needed and what generator backup and support to plan for.

"It's all about designing a system around the customer's loads and their needs and their expectations."
George, REST Energy

George from REST Energy on choosing Sigenergy for this home

System details

What we installed

Solar system: 19 kW DC (STC)
Estimated annual production: 23,818 kWh
System efficiency: 87%
Panels: 40 x 475W LONGi Hi-MO X10 Explorer (LR7-54HVH-475M), monocrystalline
Inverter: 1 x Sigenergy SigenStor EC 12.0 SP, 12 kW, single phase, 97.6% max efficiency
Battery: 45.2 kWh (45 kWh usable)
Storage: 5 x Sigenergy SigenStor 8S 9.04 kWh LiFePO4 modules (9 kWh usable each)
Mounting: Antai railless system, flush mounted on Klip-Lok 700

Production and efficiency figures are estimates.

Off-grid solar array on a home in the Derwent Valley, Tasmania

How the system fits together

Forty LONGi Hi-MO X10 Explorer panels make up the 19 kW array. They sit on an Antai railless system fixed straight to the Klip-Lok 700 roof, which keeps the panels low and tidy against the roofline.

A single phase Sigenergy SigenStor EC 12.0 SP inverter manages the system, paired with five SigenStor 8S lithium iron phosphate modules. Together they give the home 45 kWh of usable storage for the evening and for runs of cloudy weather.

Reviews

What our customers say

    
 
 
       Posted on Google  
   
   Connor C 
 
 
 
 Trustindex verifies that the original source of the review is Google. One of the easier parts of building a new house with solar. If you prefer no fuss and straight to the point service, then my hot tip is to give Rest Energy a buzz. George was beyond helpful, concise, and when a later issue popped up (due to the house and not the solar), he immediately was in contact to resolve it. I rarely leave a review on anyone, unless the product and service went above and beyond.
  
 
      Posted on Google  
   
   John Radonic 
 
 
 
 Trustindex verifies that the original source of the review is Google. My partner and I can thoroughly recommend George and his team in the highest possible way.
From the initial discussions to establish our needs, to the quoting process, then the installation itself, things could not have been smoother from our side.
This industry does receive bad press because of dodgy operators, this is certainly not the case with Rest Energy Tas, professional in all dealings, on time installation and then always there for ny ongoing queries, not that we have had many as the hand over we received was very extensive.
We can only say talk to Rest Energy with his highest recommendation
John R
  
 
      Posted on Google  
   
   john Pattison 
 
 
 
 Trustindex verifies that the original source of the review is Google. Awesome from beginning till end. Alfy, George and the crew were professional, fast and did a great job. Cant recommend them highly enough. If youre going to go solar then go with these guys. Top job team !!!
  
 
      Posted on Google  
   
   Patrick Lyness 
 
 
 
 Trustindex verifies that the original source of the review is Google. Very impressed with rest energy Tasmania. From start to finish we found Rowena, George and the whole crew to be experienced which showed in their professionalism and workmanship.
Communication was 100%.
We would highly recommend rest energy Tasmania for all your solar needs.
Wendy and Patrick Lyness.
  
 
      Posted on Google  
   
   Amanda Avens 
 
 
 
 Trustindex verifies that the original source of the review is Google. George and the team at RestEnergy have been outstanding. From the moment we engaged them in quoting, to then installing our solar system they have been very responsive and professional. Keeping us updated and involved throughout the process. A pleasure to deal with such a personable local company who pride themselves on high standards and customer service. Highly recommended.
  
 
      Posted on Google  
   
   Richard G Pritchard 
 
 
 
 Trustindex verifies that the original source of the review is Google. After the great installation of 10kW of solar panels and a Myenergi system 4 years ago by George we decided to take advantage of the recent battery support package and get a FranklinWH system for backup installed.   This has a long warranty on all parts.  Great work by George with all the tricky work done in one day.
  
 
      Posted on Google  
   
   Hamish Wakefield 
 
 
 
 Trustindex verifies that the original source of the review is Google. Excellent Service and Fantastic Results!
George and his team at Rest Energy installed our solar system in the middle of last year, and we couldn’t be happier with the results. Over summer, we actually had a credit on our power bill, and throughout winter our bill has been minimal. The system has exceeded our expectations in terms of performance and savings.

The service has also been outstanding—George has been quick to respond to any questions we've had, and his support has been consistent from installation through to follow-up. Highly recommend Rest Energy for anyone considering going solar!