The short answer: a Reddit user on r/solar says they spent about $20,000 on the "big items" for a system with 70 panels, two inverters, and two battery banks. That covers 28 kW of solar capacity and 62 kWh of battery storage. The $20K figure only covers the major equipment, so it is not the total cost of going off-grid. Below is a breakdown of what was reported, why some commenters pushed back, and how to budget for a similar project yourself.
| Component | Reported Spec |
|---|---|
| Solar panels | 70 SEG panels, 405 W each |
| Inverters | Two EG4 18KPV units |
| Battery storage | Two EG4 battery banks, 31 kWh each |
| Total solar capacity | 28 kW |
| Total storage | 62 kWh |
| Reported cost | About $20K for the big items |
What the Build Actually Was
The project was shared on r/solar and described as long-running. The poster said it was nearly finished and announced they would be going fully off-grid the next day. The reported numbers work out to 70 panels at 405 watts each, which is about 28.3 kW before real-world losses.
The setup uses two inverters and two 31 kWh battery banks. That is a large amount of storage compared with typical home systems, which is why the post drew so much attention.
What does "$20K for the big items" mean?
The poster described the figure as covering the big items only. Reading that literally, it likely excludes the smaller but necessary parts of a full installation. One commenter urged readers to set realistic expectations if they thought they could replicate the project for $20K.
Costs the $20K Figure Probably Doesn't Cover
The original post did not list these, so treat the following as a planning checklist rather than reported facts. Any large DIY solar build typically needs items beyond panels, inverters, and batteries:
- Mounting and racking: structures to hold 70 panels, whether on a roof or the ground.
- Wiring and conduit: DC cabling, connectors, and protection devices.
- Disconnects, breakers, and fuses: required for safe operation and maintenance.
- Permits and inspections: requirements vary widely by location.
- Tools and your own labor: DIY savings come largely from unpaid time.
- Shipping and freight: heavy batteries and large panel shipments can add up.
Is DIY Solar Really Cheaper?
DIY installation can reduce cost because labor is a big share of professional quotes. Other DIYers report similar savings on smaller systems. One forum user said they spent about $20K before tax credits on a 9.2 kW DC grid-tied system they installed themselves. That is a much smaller system than the one above, which shows how much costs depend on scale, equipment, and whether the system is grid-tied or off-grid.
Keep in mind: these are individual self-reports, not audited costs. Prices for equipment also change over time and vary by supplier and region.
| Factor | DIY Build | Professional Install |
|---|---|---|
| Upfront cost | Usually lower | Usually higher |
| Time required | High (this build was long-running) | Low |
| Technical skill | Significant electrical knowledge | Handled by installer |
| Workmanship warranty | Typically none | Often included |
| Permit and inspection handling | Owner's responsibility | Often handled by installer |
Who Should (and Shouldn't) Attempt a Build Like This
Good candidates
- People comfortable with electrical work, including DC wiring and panel installation.
- Owners with enough space for dozens of panels and large battery banks.
- Anyone willing to spend months planning, sourcing, and installing.
Think twice if
- You have no electrical experience and no plan to hire a licensed electrician for key steps.
- Your local rules require licensed installers or inspections you cannot arrange yourself.
- You depend on a warranty that covers installation workmanship.
Safety note: high-voltage DC and large battery banks carry real fire and shock risks. Many DIYers hire a licensed electrician for the final connection and inspection, even when they handle the rest themselves.
How to Budget for a Similar Project
- Calculate your real energy use. Review 12 months of utility bills to find daily and seasonal demand.
- Size the system to your needs. A 28 kW array is far more than many households require.
- Price the full system, not just the big items. Add racking, wiring, protection devices, permits, and shipping.
- Add a contingency. Setting aside extra for surprises is sensible on any long project.
- Check local rules and incentives. Requirements and available incentives differ by state and country.
- Get at least one professional quote. It gives you a benchmark for judging your DIY estimate.
Frequently Asked Questions
How much did the 70-panel DIY solar system cost?
The builder said about $20,000 for the big items. That is not a full project total, so the final cost was likely higher once smaller components and other expenses are included.
How much power does the system produce?
The reported capacity is 28 kW, from 70 panels rated at 405 watts each. Actual daily output depends on sunlight, panel orientation, shading, temperature, and system losses.
How much battery storage does it have?
Two battery banks of 31 kWh each, for 62 kWh in total, paired with two inverters.
Can most people build a system like this for $20K?
Not necessarily. At least one commenter warned others to be realistic about replicating it at that price. Costs vary with equipment choice, location, labor, and what you count in the total.
Is going fully off-grid a good idea?
It depends on your goals. Off-grid living gives independence but requires enough generation and storage to cover bad-weather stretches. Many people keep a grid connection as a backup.
Bottom Line
This build shows that large-scale DIY solar is possible at a price well below many professional quotes, but the $20K headline covers only the major equipment. Before copying it, price the complete system, check your local permit rules, and be honest about your electrical skills. Then compare your numbers against at least one installer quote.
Next step: read a related guide on sizing a home solar and battery system, or leave a comment with your own DIY solar experience.