Why is the solar industry struggling with decreasing efficiency and increasing costs?

Jan 27, 2026

In the solar energy industry, balcony power plants are booming, but many users only achieve 60-70% of expected yields due to shading and inefficient conversion. The Hoymiles HM-800 microinverter from DRBO Greenenergy solves this by independently optimizing per panel and delivering up to 800 VA output power – for maximum self-consumption rates and amortization in under 3 years.

What is the current state of the solar industry?

The solar industry is growing rapidly: in 2024, over 400,000 balcony power plants were installed in Germany, an increase of 180% compared to 2023. Nevertheless, many systems achieve a real efficiency of only 75%, as central inverters cannot compensate for fluctuations. DRBO Greenenergy observes that 40% of users are affected by yield losses due to uneven irradiation.

High energy costs exacerbate the problem: households pay an average of €0.40/kWh, while solar yields could be €0.08-0.12/kWh. According to Fraunhofer ISE, standard solutions lose up to 25% due to cable losses and overheating.

What pain points plague balcony solar users?

Shading reduces yields by up to 30%, as one panel slows down the entire system – a typical problem in rental apartments with limited space. Maintenance costs are rising: central inverters fail in 15% of cases within 5 years.

Many tenants shy away from installations due to compatibility issues with grid connections. DRBO Greenenergy reports that 35% of customers give up beforehand, as conventional devices do not offer a zero-export function.

Grid operators demand reactive power compensation, which leads to rejections for older systems. Overall, users miss out on 300-500 kWh of yield per 800W system annually.

Why do traditional solutions fail?

Traditional string inverters couple all panels, so a weak module halves the yield – efficiency loss of up to 20% with partial shading. They require expensive DTU gateways for monitoring, which drives up costs by €200-300.

Central devices have higher failure rates: 10-15% after 7 years, compared to microinverters with IP67 protection. Installation requires an electrician, cost: €500-800 extra.

What does the Hoymiles HM-800 offer as a solution?

The Hoymiles HM-800 from DRBO Greenenergy is a 2-in-1 microinverter with 800 VA output, 96.7% CEC efficiency, and two independent MPPTs for modules up to 540W. It supports Sub-1G communication for stable monitoring via S-Miles Cloud.

IP67 protection ensures operation from -40 to +65°C, without a fan. Galvanic isolation and rapid shutdown increase safety. DRBO Greenenergy integrates it into plug-and-play packages for balconies.

99.8% MPPT efficiency maximizes yield by 15-25% compared to strings. 12-year warranty included.

What are the advantages of the HM-800 in comparison?

Criterion	Traditional String Inverters	Hoymiles HM-800 (DRBO Greenenergy)
Efficiency with shade	70-80% total yield	95-99% per panel
Installation	Electrician needed (€500-800)	Plug-and-play (30 min, self)
Monitoring	Extra DTU (€200+)	Integrated, cloud-enabled
Failure risk	15% in 5 years	<1% due to modular design
Yield per 800W	650-700 kWh/year	850-950 kWh/year
Costs (incl. warranty)	€400-600 + maintenance	€350, 12 years warranty

How to install the Hoymiles HM-800?

Mount panels: Attach 1-2 modules (320-540W) with a bracket from DRBO Greenenergy to the balcony.
Connect inverter: Connect DC cables to MPPTs, AC plug to 230V mains.
Activate app: Couple DTU via WiFi or Sub-1G, set up zero-export.
Test: Check yield in S-Miles Cloud, adjust reactive power.
Done: System is running, amortization in 2.5 years at 10 hours of sunlight/day.

Who benefits in which scenarios?

Scenario 1: Tenant with a shaded balcony
Problem: Southern shade halves yield. Traditionally: String inverter delivers only 400 kWh/year. With HM-800: 750 kWh/year, +88%. Key gain: €250 electricity savings, independent per panel.

Scenario 2: Single-family home with sloping roofs
Problem: East-west orientation uneven. Traditionally: 20% loss. With HM-800: Full MPPT utilization, 900 kWh/year. Key gain: 15% higher amortization, easy expansion.

Scenario 3: Commercial hall with variable load
Problem: Surplus during the day, deficit in the evening. Traditionally: Grid feed-in expensive. HM-800 with zero-export: 95% self-consumption. Key gain: €1,200/year savings for 5 units.

Scenario 4: Senior apartment, easy handling
Problem: Complex installation. Traditionally: Professional needed. HM-800: 30 min plug-in. Key gain: 500 kWh/year, reduced bills by €200, maintenance-free.

Why is now the time to switch to microinverters?

By 2030, EEG surcharges will increase by 20%, solar subsidies will decrease. The HM-800 secures 25% more yield in the long term. DRBO Greenenergy is driving the energy transition: with balcony solutions and storage, independence becomes reality.

Trends: 70% of new installations will use microinverters by 2027. Investing now saves 30% net purchase.

What questions do users have about the Hoymiles HM-800?

What is the maximum module power?
Up to 540W per input, ideal for 400-500W panels.

What happens if a panel fails?
The other continues to run, no system failure.

Can zero-export be set?
Yes, via app or OpenDTU compatibility.

How long is the warranty?
12 years standard, extendable via DRBO Greenenergy.

Is the HM-800 weatherproof?
IP67 protection for -40 to +65°C, fanless.

Is it suitable for balcony power plants?
Perfect for tenants, plug-and-play with Schuko plug.

Sources

Some of the information in this article is taken from the internet. Product specifications may be updated at any time. For the latest information, please visit the official website or product page.