Software · head to head
Stem Athena vs Helioscope
The short version
- Only Helioscope has a free tier, so it costs nothing to try first.
- Each has a real cost: Stem Athena stem's site names the product PowerTrack Optimizer, formerly Athena, so the Athena name is retired; Helioscope licences are single user, so each designer needs their own
- They diverge on capability: Stem Athena covers AI optimization, Helioscope covers PV system design.
Where they differ
Only the attributes on which Stem Athena and Helioscope actually diverge.
| Attribute | Stem Athena | Helioscope |
|---|---|---|
| Starting price | On request | Free |
| Free tier | No | Yes |
| Platforms | Web, Mobile, Api | Web, Api |
| Founded | 2009 | 2012 |
Identical on both: pricing model (subscription), user rating (Not yet rated), category (Unknown).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Stem Athena
- AI optimization
- Energy storage management
- Demand charge reduction
- Grid services
- Solar integration
- Weather forecasting
- Performance analytics
- Remote monitoring
Only in Helioscope
- PV system design
- 3D shade modeling
- Performance simulation
- Single-line diagrams
- BOM generation
- Proposal templates
- Component database
- Financial modeling
Both cover
- SOC2
- Cloud deployment
What people use each for
The jobs each tool is most often brought in to do.
Stem Athena
- Optimising dispatch and market participation of battery energy storagenot Helioscope
- Monitoring and reporting on solar and storage asset performancenot Helioscope
- Remote diagnostics across renewable generation fleetsnot Helioscope
Helioscope
- Simulating photovoltaic system performance and energy yieldnot Stem Athena
- Laying out commercial solar arrays and producing design reportsnot Stem Athena
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Stem Athena
- Stem's site names the product PowerTrack Optimizer, formerly Athena, so the Athena name is retired
- No price, subscription fee or contract term is published anywhere on the site
- The optimizer is one component of the wider PowerTrack suite alongside separate EMS, SCADA, Power Plant Controller and Logger products rather than a standalone licence
- Design, procurement, commissioning and operation are sold as managed services separate from the software
Helioscope
- Licences are single user, so each designer needs their own
- Projects are capped at 10 a month on both Basic and Pro
- System size is capped by plan, at 1.25 MW DC on Basic and 5 MW on Pro, so a larger array forces an upgrade regardless of project count
- Trackers, LIDAR modelling and API access sit on the higher tiers
- Enterprise is priced per project with no published figure
Pricing, plan by plan
Stem Athena
On request- Commercial$undefined/custom
- Energy storage optimization
- Demand charge management
- Rate optimization
- Utility$undefined/custom
- Grid services
- VPP management
- Frequency regulation
- Enterprise$undefined/custom
- Fleet management
- Portfolio optimization
- Custom integrations
Helioscope
Free- FreeFree
- 3 projects
- Basic design tools
- Shade analysis
- Professional$95/month
- Unlimited projects
- Advanced shading
- Custom reports
- Enterprise$undefined/month
- Everything in Pro
- API access
- Custom integrations
Which should you pick?
Choose Stem Athena if
- You need ai optimization.
- You work on Web, Mobile, Api.
- You also want energy storage management.
Choose Helioscope if
- You need pv system design.
- You want to start without paying.
- You work on Web, Api.
- You also want 3d shade modeling.
Questions people ask
- Is Stem Athena or Helioscope better?
- Neither clearly leads. Stem Athena starts at On request and Helioscope at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Stem Athena or Helioscope?
- Helioscope has a free tier; the other does not. Paid plans start at On request for Stem Athena and Free for Helioscope.
- Does Stem Athena or Helioscope run on more platforms?
- Stem Athena runs on Web, Mobile, Api. Helioscope runs on Web, Api.
- Can I use Helioscope for free?
- Yes. Helioscope has a free tier, so you can try it without paying. Stem Athena starts at On request.
- What is Stem Athena best used for?
- Stem Athena is most often used for optimising dispatch and market participation of battery energy storage, monitoring and reporting on solar and storage asset performance, remote diagnostics across renewable generation fleets. Of those, optimising dispatch and market participation of battery energy storage and monitoring and reporting on solar and storage asset performance are not what Helioscope is typically brought in for.
- What can Stem Athena do that Helioscope cannot?
- Stem Athena covers AI optimization, Energy storage management, Demand charge reduction, Grid services. Helioscope covers PV system design, 3D shade modeling, Performance simulation, Single-line diagrams. Both handle SOC2, Cloud deployment.