Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: der.la$la_per_kW ~ der.la$Treatment + (1 | as.factor(der.la$Expt_no))

REML criterion at convergence: 27.4

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-1.27413 -0.38450 -0.07327  0.44367  1.30777 

Random effects:
 Groups                    Name        Variance Std.Dev.
 as.factor(der.la$Expt_no) (Intercept) 1.7968   1.3405  
 Residual                              0.1088   0.3299  
Number of obs: 12, groups:  as.factor(der.la$Expt_no), 6

Fixed effects:
                         Estimate Std. Error     df t value Pr(>|t|)    
(Intercept)                7.8266     0.5636 5.2937   13.89 2.29e-05 ***
der.la$TreatmentFeedback   1.9584     0.1905 5.0000   10.28  0.00015 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Correlation of Fixed Effects:
            (Intr)
dr.l$TrtmnF -0.169
