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We serve MA, NH, CT, RI, ME, VT, NJ, PA, and TX
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NuWatt designs, installs, and manages solar, battery, heat pump, and EV charger systems across 9 states. One company, one warranty, one point of contact.
Get a Free QuoteWhich is better for your home? We install both. Here's our honest, spec-by-spec comparison based on real installation experience.
The REC Alpha Pure-RX 470W wins this head-to-head comparison, taking 3 out of 5 categories. It's the stronger choice for most homeowners, especially those who prioritize maximum energy per square foot. That said, the Silfab SIL-420 BG Elite 420W is still a solid product and may be the better pick if you specifically need homeowners who want american-made panels.
Silfab · SIL-420 BG Elite
REC · Alpha Pure-RX 470
| Spec | Silfab | REC |
|---|---|---|
| Wattage | 420W | 470W |
| Efficiency | 21.9% | 22.6% |
| Temp Coefficient | -0.34%/°C | -0.26%/°C |
| Degradation Rate | 0.50%/yr (87.5% at year 25) | 0.25%/yr (92% at year 25) |
| Cell Type | Monocrystalline, X-pattern backsheet | Heterojunction (HJT), gapless |
| Dimensions | 40.5 x 73.4 x 1.4 in (1029 x 1864 mm) | 42.5 x 74.3 x 1.2 in (1080 x 1890 mm) |
| Weight | 45.8 lbs (20.8 kg) | 46.3 lbs (21 kg) |
| Origin | USA (Burlington, WA) | Norway / Singapore |
| Frame | Black anodized aluminum | Black anodized aluminum |
We evaluate each product across the metrics that matter most to homeowners.
Both offer 25-year warranties.
Silfab SIL-420 BG Elite 420W is more affordable at $1.10-1.30/W (panel only) vs $1.30-1.50/W (panel only).
Our crew rates the REC Alpha Pure-RX 470W higher at 9.5/10 vs 8.5/10.
REC Alpha Pure-RX 470W is more efficient at 22.6% vs 21.9%.
REC Alpha Pure-RX 470W degrades more slowly at 0.25%/yr (92% at year 25) vs 0.50%/yr (87.5% at year 25).
Silfab is our American-made pick. The panels are slightly lighter than Q CELLS, which crews appreciate on steep roofs. The X-pattern backsheet technology gives solid efficiency without N-type cell costs. We recommend Silfab especially for commercial projects where the domestic content ITC adder adds real savings. Reliable supply chain — no tariff or FEOC concerns.
REC Alpha Pure-RX is our go-to premium panel. The 470W output means fewer panels for the same system size, which reduces racking hardware and labor. HJT cells have near-zero LID (light-induced degradation), so these panels produce at full rated power from day one. We recommend REC for space-constrained roofs where every watt per square foot counts.
The REC Alpha Pure-RX 470W wins this head-to-head comparison, taking 3 out of 5 categories. It's the stronger choice for most homeowners, especially those who prioritize maximum energy per square foot. That said, the Silfab SIL-420 BG Elite 420W is still a solid product and may be the better pick if you specifically need homeowners who want american-made panels.
Our energy advisors can help you decide between the Silfab SIL-420 BG Elite 420W and REC Alpha Pure-RX 470W based on your specific home, budget, and energy goals.
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